diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0e6acbd3..65e899c9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Read environment variables from `/etc/default/warewulfd` #725
 - Add support for VLANs to NetworkManager, wicked, ifcfg, debian.network_interfaces overlays. #1257
 - Add support for static routes to NetworkManager, wicked, ifcfg, debian.network_interfaces overlays. #1257
+- Add `wwctl upgrade <config|nodes>`. #230, #517
 
 ### Changed
 
diff --git a/cmd/update_configuration/update_configuration.go b/cmd/update_configuration/update_configuration.go
deleted file mode 100644
index bc394445..00000000
--- a/cmd/update_configuration/update_configuration.go
+++ /dev/null
@@ -1,182 +0,0 @@
-package main
-
-import (
-	"flag"
-	"fmt"
-	"os"
-	"reflect"
-
-	"github.com/warewulf/warewulf/cmd/update_configuration/vers42"
-	"github.com/warewulf/warewulf/cmd/update_configuration/vers43"
-	"github.com/warewulf/warewulf/internal/pkg/util"
-	"gopkg.in/yaml.v3"
-)
-
-var nowrite bool
-var quiet bool
-var confFile string
-
-const actvers int = 43
-
-type nodeVersionOnly struct {
-	WWInternal int `yaml:"WW_INTERNAL"`
-}
-
-func saveConf(conf interface{}) {
-	out, err := yaml.Marshal(conf)
-	if err != nil {
-		myprintf("Error in marshal of conf: %s\n", err)
-		os.Exit(1)
-	}
-	if nowrite {
-		fmt.Print(string(out))
-	} else {
-		err = util.CopyFile(confFile, confFile+".bak")
-		if err != nil {
-			myprintf("Could write file: %s\n", err)
-			os.Exit(1)
-		}
-		info, err := os.Stat(confFile)
-		if err != nil {
-			myprintf("Could not get file mode: %s\n", err)
-			os.Exit(1)
-		}
-		myprintf("writing configuration file %s as type %s\n", confFile, reflect.TypeOf(conf))
-		err = os.WriteFile(confFile, out, info.Mode())
-		if err != nil {
-			myprintf("Could not write file: %s\n", err)
-			os.Exit(1)
-		}
-	}
-}
-
-func printB(x bool) string {
-	if x {
-		return "true"
-	}
-	return "false"
-}
-
-func update42to43(conf42 vers42.NodeConf) vers43.NodeConf {
-	ret := vers43.NodeConf{
-		Comment:       conf42.Comment,
-		ClusterName:   conf42.ClusterName,
-		ContainerName: conf42.ContainerName,
-		Init:          conf42.Init,
-		Root:          conf42.Root,
-		Discoverable:  printB(conf42.Discoverable),
-		Profiles:      conf42.Profiles,
-		Ipxe:          conf42.Ipxe}
-	if conf42.RuntimeOverlay != "" {
-		ret.RuntimeOverlay = []string{conf42.RuntimeOverlay}
-	}
-	if conf42.SystemOverlay != "" {
-		ret.SystemOverlay = []string{conf42.SystemOverlay}
-	}
-	if conf42.KernelArgs != "" || conf42.KernelVersion != "" {
-		ret.Kernel = new(vers43.KernelConf)
-		ret.Kernel.Override = conf42.KernelVersion
-		ret.Kernel.Args = conf42.KernelArgs
-
-	}
-	if conf42.IpmiUserName != "" || conf42.IpmiPassword != "" || conf42.IpmiIpaddr != "" ||
-		conf42.IpmiNetmask != "" || conf42.IpmiPort != "" || conf42.IpmiGateway != "" ||
-		conf42.IpmiInterface != "" {
-		ret.Ipmi = new(vers43.IpmiConf)
-		ret.Ipmi.UserName = conf42.IpmiUserName
-		ret.Ipmi.Password = conf42.IpmiPassword
-		ret.Ipmi.Ipaddr = conf42.IpmiIpaddr
-		ret.Ipmi.Netmask = conf42.IpmiNetmask
-		ret.Ipmi.Port = conf42.IpmiPort
-		ret.Ipmi.Gateway = conf42.IpmiGateway
-		ret.Ipmi.Interface = conf42.IpmiInterface
-	}
-	if len(conf42.Keys) != 0 {
-		ret.Keys = map[string]string{}
-		for k, v := range conf42.Keys {
-			ret.Keys[k] = v
-		}
-	}
-	ret.NetDevs = make(map[string]*vers43.NetDevs)
-	for devn, netdev := range conf42.NetDevs {
-		var device vers43.NetDevs = vers43.NetDevs{
-			Type:    netdev.Type,
-			Device:  devn,
-			Primary: printB(netdev.Default),
-			Hwaddr:  netdev.Hwaddr,
-			Ipaddr:  netdev.Ipaddr,
-			IpCIDR:  netdev.IpCIDR,
-			Prefix:  netdev.Prefix,
-			Netmask: netdev.Netmask,
-			Gateway: netdev.Gateway}
-		ret.NetDevs[devn] = &device
-	}
-	return ret
-}
-
-func myprintf(format string, a ...interface{}) {
-	if !quiet {
-		fmt.Printf(format, a...)
-	}
-}
-
-func main() {
-	var endVers int
-	var startVers int
-	flag.StringVar(&confFile, "f", "", "Config file for update")
-	flag.IntVar(&endVers, "e", 0, "Final version of configuration file")
-	flag.IntVar(&startVers, "s", 0, "Start version  of configuration file, 0  is for autodetection")
-	flag.BoolVar(&nowrite, "n", false, "Do not write, just print new conf to terminal")
-	flag.BoolVar(&quiet, "q", false, "Do not print what the program is doing")
-	flag.Parse()
-	if confFile == "" {
-		myprintf("No config file given\n!")
-		os.Exit(1)
-	}
-	myprintf("Opening node configuration file: %s\n", confFile)
-	data, err := os.ReadFile(confFile)
-	if err != nil {
-		myprintf("Could open file %v\n", err)
-		os.Exit(1)
-	}
-	var getConf nodeVersionOnly
-	myprintf("Unmarshaling the node configuration\n")
-	err = yaml.Unmarshal(data, &getConf)
-	if err != nil {
-		myprintf("Could not unmarshall: %v\n", err)
-	}
-	myprintf("Got version %v in %s\n", getConf.WWInternal, confFile)
-	if getConf.WWInternal == actvers {
-		myprintf("On actual version, bailing out\n")
-		os.Exit(0)
-	}
-	if startVers == 0 && getConf.WWInternal == 0 {
-		startVers = 42
-	}
-	var conf42 vers42.NodeYaml
-	conf42.NodeProfiles = make(map[string]*vers42.NodeConf)
-	conf42.Nodes = make(map[string]*vers42.NodeConf)
-
-	var conf43 vers43.NodeYaml
-	conf43.NodeProfiles = make(map[string]*vers43.NodeConf)
-	conf43.Nodes = make(map[string]*vers43.NodeConf)
-	conf43.WWInternal = 43
-
-	if startVers == 42 {
-		myprintf("Unmarshaling the node configuration vers 42\n")
-		err = yaml.Unmarshal(data, &conf42)
-		if err != nil {
-			myprintf("Could not unmarshall version 42: %v\n", err)
-		}
-		for pname, profile := range conf42.NodeProfiles {
-			p43 := update42to43(*profile)
-			conf43.NodeProfiles[pname] = &p43
-		}
-		for nname, node := range conf42.Nodes {
-			n43 := update42to43(*node)
-			conf43.Nodes[nname] = &n43
-		}
-		saveConf(conf43)
-
-	}
-}
diff --git a/cmd/update_configuration/vers42/datastructure.go b/cmd/update_configuration/vers42/datastructure.go
deleted file mode 100644
index 188419d8..00000000
--- a/cmd/update_configuration/vers42/datastructure.go
+++ /dev/null
@@ -1,46 +0,0 @@
-package vers42
-
-/******
- * YAML data representations
- ******/
-
-// type nodeYaml struct {
-type NodeYaml struct { // <-Needs to be exported
-	NodeProfiles map[string]*NodeConf
-	Nodes        map[string]*NodeConf
-}
-
-type NodeConf struct {
-	Comment        string              `yaml:"comment,omitempty"`
-	ClusterName    string              `yaml:"cluster name,omitempty"`
-	ContainerName  string              `yaml:"container name,omitempty"`
-	Ipxe           string              `yaml:"ipxe template,omitempty"`
-	KernelVersion  string              `yaml:"kernel version,omitempty"`
-	KernelArgs     string              `yaml:"kernel args,omitempty"`
-	IpmiUserName   string              `yaml:"ipmi username,omitempty"`
-	IpmiPassword   string              `yaml:"ipmi password,omitempty"`
-	IpmiIpaddr     string              `yaml:"ipmi ipaddr,omitempty"`
-	IpmiNetmask    string              `yaml:"ipmi netmask,omitempty"`
-	IpmiPort       string              `yaml:"ipmi port,omitempty"`
-	IpmiGateway    string              `yaml:"ipmi gateway,omitempty"`
-	IpmiInterface  string              `yaml:"ipmi interface,omitempty"`
-	RuntimeOverlay string              `yaml:"runtime overlay,omitempty"`
-	SystemOverlay  string              `yaml:"system overlay,omitempty"`
-	Init           string              `yaml:"init,omitempty"`
-	Root           string              `yaml:"root,omitempty"`
-	Discoverable   bool                `yaml:"discoverable,omitempty"`
-	Profiles       []string            `yaml:"profiles,omitempty"`
-	NetDevs        map[string]*NetDevs `yaml:"network devices,omitempty"`
-	Keys           map[string]string   `yaml:"keys,omitempty"`
-}
-
-type NetDevs struct {
-	Type    string `yaml:"type,omitempty"`
-	Default bool   `yaml:"default"`
-	Hwaddr  string
-	Ipaddr  string
-	IpCIDR  string
-	Prefix  string
-	Netmask string
-	Gateway string `yaml:"gateway,omitempty"`
-}
diff --git a/cmd/update_configuration/vers42/nodes.conf b/cmd/update_configuration/vers42/nodes.conf
deleted file mode 100644
index 792e48a2..00000000
--- a/cmd/update_configuration/vers42/nodes.conf
+++ /dev/null
@@ -1,22 +0,0 @@
-nodeprofiles:
-  default:
-    comment: This profile is automatically included for each node
-    runtime overlay: "generic"
-    discoverable: false
-  leap:
-    comment: openSUSE leap
-    kernel version: "5.14.21"
-    ipmi netmask: "255.255.255.0"
-    keys:
-      foo: baar
-    network devices:
-      lan1:
-        gateway: 1.1.1.1
-nodes:
-  node01:
-    system overlay: "nodeoverlay"
-    discoverable: true
-    network devices:
-      eth0:
-        ipaddr: 1.2.3.4
-        default: true
diff --git a/cmd/update_configuration/vers43/datastructure.go b/cmd/update_configuration/vers43/datastructure.go
deleted file mode 100644
index 24e8f185..00000000
--- a/cmd/update_configuration/vers43/datastructure.go
+++ /dev/null
@@ -1,65 +0,0 @@
-package vers43
-
-/******
- * YAML data representations
- ******/
-
-// type nodeYaml struct {
-type NodeYaml struct { // <- needs to be exported
-	WWInternal   int `yaml:"WW_INTERNAL"`
-	NodeProfiles map[string]*NodeConf
-	Nodes        map[string]*NodeConf
-}
-
-/*
-NodeConf is the datastructure which is stored on disk.
-*/
-type NodeConf struct {
-	Comment        string              `yaml:"comment,omitempty"`
-	ClusterName    string              `yaml:"cluster name,omitempty"`
-	ContainerName  string              `yaml:"container name,omitempty"`
-	Ipxe           string              `yaml:"ipxe template,omitempty"`
-	RuntimeOverlay []string            `yaml:"runtime overlay,omitempty"`
-	SystemOverlay  []string            `yaml:"system overlay,omitempty"`
-	Kernel         *KernelConf         `yaml:"kernel,omitempty"`
-	Ipmi           *IpmiConf           `yaml:"ipmi,omitempty"`
-	Init           string              `yaml:"init,omitempty"`
-	Root           string              `yaml:"root,omitempty"`
-	AssetKey       string              `yaml:"asset key,omitempty"`
-	Discoverable   string              `yaml:"discoverable,omitempty"`
-	Profiles       []string            `yaml:"profiles,omitempty"`
-	NetDevs        map[string]*NetDevs `yaml:"network devices,omitempty"`
-	Tags           map[string]string   `yaml:"tags,omitempty"`
-	Keys           map[string]string   `yaml:"keys,omitempty"` // Reverse compatibility
-}
-
-type IpmiConf struct {
-	UserName  string `yaml:"username,omitempty"`
-	Password  string `yaml:"password,omitempty"`
-	Ipaddr    string `yaml:"ipaddr,omitempty"`
-	Netmask   string `yaml:"netmask,omitempty"`
-	Port      string `yaml:"port,omitempty"`
-	Gateway   string `yaml:"gateway,omitempty"`
-	Interface string `yaml:"interface,omitempty"`
-	Write     bool   `yaml:"write,omitempty"`
-}
-type KernelConf struct {
-	Version  string `yaml:"version,omitempty"`
-	Override string `yaml:"override,omitempty"`
-	Args     string `yaml:"args,omitempty"`
-}
-
-type NetDevs struct {
-	Type    string            `yaml:"type,omitempty"`
-	OnBoot  string            `yaml:"onboot,omitempty"`
-	Device  string            `yaml:"device,omitempty"`
-	Hwaddr  string            `yaml:"hwaddr,omitempty"`
-	Ipaddr  string            `yaml:"ipaddr,omitempty"`
-	IpCIDR  string            `yaml:"ipcidr,omitempty"`
-	Ipaddr6 string            `yaml:"ip6addr,omitempty"`
-	Prefix  string            `yaml:"prefix,omitempty"`
-	Netmask string            `yaml:"netmask,omitempty"`
-	Gateway string            `yaml:"gateway,omitempty"`
-	Primary string            `yaml:"primary,omitempty"`
-	Tags    map[string]string `yaml:"tags,omitempty"`
-}
diff --git a/cmd/update_configuration/vers43/nodes.conf b/cmd/update_configuration/vers43/nodes.conf
deleted file mode 100644
index 22772050..00000000
--- a/cmd/update_configuration/vers43/nodes.conf
+++ /dev/null
@@ -1,32 +0,0 @@
-WW_INTERNAL: 45
-nodeprofiles:
-  default:
-    comment: This profile is automatically included for each node
-    runtime overlay:
-    - generic
-    discoverable: "false"
-  leap:
-    comment: openSUSE leap
-    kernel:
-      override: 5.14.21
-    ipmi:
-      netmask: 255.255.255.0
-    discoverable: "false"
-    network devices:
-      lan1:
-        device: lan1
-        gateway: 1.1.1.1
-        default: "false"
-    keys:
-      foo: baar
-nodes:
-  node01:
-    system overlay:
-    - nodeoverlay
-    discoverable: "true"
-    network devices:
-      eth0:
-        device: eth0
-        ipaddr: 1.2.3.4
-        default: "true"
-
diff --git a/docs/man/man5/warewulf.conf.5 b/docs/man/man5/warewulf.conf.5
index 78716a41..bb22172d 100644
--- a/docs/man/man5/warewulf.conf.5
+++ b/docs/man/man5/warewulf.conf.5
@@ -16,12 +16,6 @@ warewulf.conf is defined using YAML document markup syntax.
 .LP
 The configuration parameters available include:
 
-.TP
-\fBWW_INTERNAL\fP
-Specifies the version of the configuration file format. The current
-version is 43.
-.IP
-
 .TP
 \fBipaddr\fP
 This is the control node's networking interface connecting to the
@@ -279,7 +273,6 @@ A sample configuration file for a typical deployment, with all
 dependent services enabled.
 
 .EX
-WW_INTERNAL: 45
 ipaddr: 10.0.0.1
 network: 10.0.0.0
 netmask: 255.255.0.0
diff --git a/etc/nodes.conf b/etc/nodes.conf
index 62d5b496..1b8c983a 100644
--- a/etc/nodes.conf
+++ b/etc/nodes.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 46
 nodeprofiles:
   default:
     comment: This profile is automatically included for each node
diff --git a/etc/warewulf.conf b/etc/warewulf.conf
index ae9203e4..b0589a91 100644
--- a/etc/warewulf.conf
+++ b/etc/warewulf.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 45
 ipaddr: 10.0.0.1
 netmask: 255.255.252.0
 warewulf:
diff --git a/internal/app/wwclient/root.go b/internal/app/wwclient/root.go
index 3e1fa799..8034deb2 100644
--- a/internal/app/wwclient/root.go
+++ b/internal/app/wwclient/root.go
@@ -102,7 +102,7 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	if conf.WWClient != nil && conf.WWClient.Port > 0 {
 		localTCPAddr.Port = int(conf.WWClient.Port)
 		wwlog.Info("Running from configured port %d", conf.WWClient.Port)
-	} else if conf.Warewulf.Secure {
+	} else if conf.Warewulf.Secure() {
 		// Setup local port to something privileged (<1024)
 		localTCPAddr.Port = 987
 		wwlog.Info("Running from trusted port")
diff --git a/internal/app/wwctl/clean/main_test.go b/internal/app/wwctl/clean/main_test.go
index 23d8c38b..6396e8bd 100644
--- a/internal/app/wwctl/clean/main_test.go
+++ b/internal/app/wwctl/clean/main_test.go
@@ -12,8 +12,7 @@ func Test_Clean(t *testing.T) {
 	wwlog.SetLogLevel(wwlog.DEBUG)
 	env := testenv.New(t)
 	env.WriteFile(t, "etc/warewulf/nodes.conf",
-		`WW_INTERNAL: 45
-nodeprofiles: {}
+		`nodeprofiles: {}
 nodes:
   node1: {}
 `)
diff --git a/internal/app/wwctl/container/exec/child/main.go b/internal/app/wwctl/container/exec/child/main.go
index 9e9c064f..455ef9f9 100644
--- a/internal/app/wwctl/container/exec/child/main.go
+++ b/internal/app/wwctl/container/exec/child/main.go
@@ -134,14 +134,14 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	}
 
 	for _, mntPnt := range mountPts {
-		if mntPnt.Copy {
+		if mntPnt.Copy() {
 			continue
 		}
 		wwlog.Debug("bind mounting: %s -> %s", mntPnt.Source, path.Join(containerPath, mntPnt.Dest))
 		err = syscall.Mount(mntPnt.Source, path.Join(containerPath, mntPnt.Dest), "", syscall.MS_BIND, "")
 		if err != nil {
 			wwlog.Warn("Couldn't mount %s to %s: %s", mntPnt.Source, mntPnt.Dest, err)
-		} else if mntPnt.ReadOnly {
+		} else if mntPnt.ReadOnly() {
 			err = syscall.Mount(mntPnt.Source, path.Join(containerPath, mntPnt.Dest), "", syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_BIND, "")
 			if err != nil {
 				wwlog.Warn("failed to following mount readonly: %s", mntPnt.Source)
@@ -191,7 +191,7 @@ the invalid mount points. Directories always have '/' as suffix
 func checkMountPoints(containerName string, binds []*warewulfconf.MountEntry) (overlayObjects []string) {
 	overlayObjects = []string{}
 	for _, b := range binds {
-		if b.Copy {
+		if b.Copy() {
 			continue
 		}
 		_, err := os.Stat(b.Source)
diff --git a/internal/app/wwctl/container/exec/main.go b/internal/app/wwctl/container/exec/main.go
index 195775e4..a087338c 100644
--- a/internal/app/wwctl/container/exec/main.go
+++ b/internal/app/wwctl/container/exec/main.go
@@ -229,7 +229,7 @@ Check the objects we want to copy in, instead of mounting
 */
 func getCopyFiles(binds []*warewulfconf.MountEntry) (copyObjects []*copyFile) {
 	for _, bind := range binds {
-		if bind.Copy {
+		if bind.Copy() {
 			copyObjects = append(copyObjects, &copyFile{
 				fileName: bind.Dest,
 				src:      bind.Source,
diff --git a/internal/app/wwctl/container/list/main_test.go b/internal/app/wwctl/container/list/main_test.go
index 1e841128..1baf769c 100644
--- a/internal/app/wwctl/container/list/main_test.go
+++ b/internal/app/wwctl/container/list/main_test.go
@@ -29,7 +29,7 @@ CONTAINER NAME  NODES  KERNEL VERSION  CREATION TIME        MODIFICATION TIME
 --------------  -----  --------------  -------------        -----------------    ----
 test            1      kernel          01 Jan 70 00:00 UTC  01 Jan 70 00:00 UTC  0 B
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
diff --git a/internal/app/wwctl/node/add/main_test.go b/internal/app/wwctl/node/add/main_test.go
index 01a2811c..104cca51 100644
--- a/internal/app/wwctl/node/add/main_test.go
+++ b/internal/app/wwctl/node/add/main_test.go
@@ -23,8 +23,7 @@ func Test_Add(t *testing.T) {
 			args:    []string{"n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -34,8 +33,7 @@ nodes:
 			args:    []string{"--profile=foo", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -45,8 +43,7 @@ nodes:
 			args:    []string{"--discoverable=true", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     discoverable: "true"
@@ -57,8 +54,7 @@ nodes:
 			args:    []string{"--discoverable", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     discoverable: "true"
@@ -70,16 +66,14 @@ nodes:
 			wantErr: true,
 			stdout:  "",
 			chkout:  false,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes: {}
 `},
 		{name: "single node add, discoverable false",
 			args:    []string{"--discoverable=false", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     discoverable: "false"
@@ -90,8 +84,7 @@ nodes:
 			args:    []string{"--kernelargs=foo", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     kernel:
@@ -103,8 +96,7 @@ nodes:
 			args:    []string{"n01", "n02"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -117,8 +109,7 @@ nodes:
 			args:    []string{"--ipaddr6=fdaa::1", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -131,8 +122,7 @@ nodes:
 			args:    []string{"--ipaddr=10.0.0.1", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -146,16 +136,14 @@ nodes:
 			wantErr: true,
 			stdout:  "",
 			chkout:  false,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes: {}
 `},
 		{name: "three nodes with ipaddr",
 			args:    []string{"--ipaddr=10.10.0.1", "n[01-02,03]"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -180,8 +168,7 @@ nodes:
 			args:    []string{"--ipaddr=10.10.0.1", "--netname=foo", "n[01-03]"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -206,8 +193,7 @@ nodes:
 			args:    []string{"--ipaddr=10.10.0.1", "--netname=foo", "--ipmiaddr=10.20.0.1", "n[01-03]"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     ipmi:
@@ -238,8 +224,7 @@ nodes:
 			args:    []string{"--fsname=/dev/vda1", "--fspath=/var", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -252,16 +237,14 @@ nodes:
 			args:    []string{"--fsname=dev/vda1", "--fspath=/var", "n01"},
 			wantErr: true,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes: {}
 `},
 		{name: "one node with filesystem and partition ",
 			args:    []string{"--fsname=var", "--fspath=/var", "--partname=var", "--diskname=/dev/vda", "--partnumber=1", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -279,8 +262,7 @@ nodes:
 			args:    []string{"--fsname=var", "--fspath=/var", "--fsformat=btrfs", "--partname=var", "--diskname=/dev/vda", "--partnumber=1", "n01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -299,8 +281,7 @@ nodes:
 	warewulfd.SetNoDaemon()
 	for _, tt := range tests {
 		env := testenv.New(t)
-		env.WriteFile(t, "etc/warewulf/nodes.conf",
-			`WW_INTERNAL: 45`)
+		env.WriteFile(t, "etc/warewulf/nodes.conf", ``)
 		var err error
 		t.Run(tt.name, func(t *testing.T) {
 			baseCmd := GetCommand()
diff --git a/internal/app/wwctl/node/add/root.go b/internal/app/wwctl/node/add/root.go
index 4fb7e5e8..4626e325 100644
--- a/internal/app/wwctl/node/add/root.go
+++ b/internal/app/wwctl/node/add/root.go
@@ -12,7 +12,7 @@ import (
 
 // Holds the variables which are needed in CobraRunE
 type variables struct {
-	nodeConf node.NodeConf
+	nodeConf node.Node
 	nodeAdd  node.NodeConfAdd
 }
 
diff --git a/internal/app/wwctl/node/delete/main.go b/internal/app/wwctl/node/delete/main.go
index 40ad2554..7da7c19f 100644
--- a/internal/app/wwctl/node/delete/main.go
+++ b/internal/app/wwctl/node/delete/main.go
@@ -18,7 +18,7 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	}
 
 	if !SetYes {
-		var nodeList []node.NodeConf
+		var nodeList []node.Node
 		// The checks run twice in the prompt case.
 		// Avoiding putting in a blocking prompt in an API.
 		nodeList, err = apiNode.NodeDeleteParameterCheck(&ndp, false)
diff --git a/internal/app/wwctl/node/edit/main.go b/internal/app/wwctl/node/edit/main.go
index 34660743..82a81f43 100644
--- a/internal/app/wwctl/node/edit/main.go
+++ b/internal/app/wwctl/node/edit/main.go
@@ -38,7 +38,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		Output: args,
 	}
 	nodeListMsg := apinode.FilteredNodes(&filterList)
-	nodeMap := make(map[string]*node.NodeConf)
+	nodeMap := make(map[string]*node.Node)
 	// got proper yaml back
 	_ = yaml.Unmarshal([]byte(nodeListMsg.NodeConfMapYaml), nodeMap)
 	file, err := os.CreateTemp(os.TempDir(), "ww4NodeEdit*.yaml")
@@ -50,7 +50,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		_ = file.Truncate(0)
 		_, _ = file.Seek(0, 0)
 		if !NoHeader {
-			yamlTemplate := node.UnmarshalConf(node.NodeConf{}, []string{"tagsdel"})
+			yamlTemplate := node.UnmarshalConf(node.Node{}, []string{"tagsdel"})
 			_, _ = file.WriteString("#nodename:\n#  " + strings.Join(yamlTemplate, "\n#  ") + "\n")
 		}
 		_, _ = file.WriteString(nodeListMsg.NodeConfMapYaml)
@@ -73,7 +73,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		wwlog.Debug("Hashes are before %s and after %s\n", sum1, sum2)
 		if sum1 != sum2 {
 			wwlog.Debug("Nodes were modified")
-			modifiedNodeMap := make(map[string]*node.NodeConf)
+			modifiedNodeMap := make(map[string]*node.Node)
 			_, _ = file.Seek(0, 0)
 			// ignore error as only may occurs under strange circumstances
 			buffer, _ := io.ReadAll(file)
diff --git a/internal/app/wwctl/node/imprt/main.go b/internal/app/wwctl/node/imprt/main.go
index 2a7156c2..5bc1e81c 100644
--- a/internal/app/wwctl/node/imprt/main.go
+++ b/internal/app/wwctl/node/imprt/main.go
@@ -22,7 +22,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 	}
 	defer file.Close()
 
-	importMap := make(map[string]*node.NodeConf)
+	importMap := make(map[string]*node.Node)
 	buffer, err := io.ReadAll(file)
 	if err != nil {
 		return fmt.Errorf("could not read: %s", err)
@@ -64,7 +64,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 					continue
 				}
 				if importMap[line[0]] == nil {
-					importMap[line[0]] = new(node.NodeConf)
+					importMap[line[0]] = new(node.Node)
 				}
 			}
 		}
diff --git a/internal/app/wwctl/node/list/main_test.go b/internal/app/wwctl/node/list/main_test.go
index f0a24793..b39c385e 100644
--- a/internal/app/wwctl/node/list/main_test.go
+++ b/internal/app/wwctl/node/list/main_test.go
@@ -32,8 +32,7 @@ NODE NAME  PROFILES   NETWORK
 ---------  --------   -------
 n01        [default]  --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default: {}
 nodes:
   n01:
@@ -51,8 +50,7 @@ NODE NAME  PROFILES   NETWORK
 n01        [default]  --
 n02        [default]  --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default: {}
 nodes:
   n01:
@@ -73,8 +71,7 @@ NODE NAME  PROFILES   NETWORK
 n01        [default]  --
 n02        [default]  --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default: {}
 nodes:
   n01:
@@ -95,8 +92,7 @@ NODE NAME  PROFILES   NETWORK
 n01        [default]  --
 n03        [default]  --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default: {}
 nodes:
   n01:
@@ -125,8 +121,7 @@ NODE NAME  PROFILES   NETWORK
 ---------  --------   -------
 n01        [default]  --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default: {}
 nodes:
   n01:
@@ -146,8 +141,7 @@ NODE NAME  PROFILES   NETWORK
 ---------  --------   -------
 n01        [default]  default
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default:
     network devices:
       default:
@@ -168,8 +162,7 @@ NODE  FIELD     PROFILE  VALUE
 n01   Comment   default  profilecomment
 n01   Profiles  --       default
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default:
     comment: profilecomment
 nodes:
@@ -188,8 +181,7 @@ NODE  FIELD     PROFILE     VALUE
 n01   Comment   SUPERSEDED  nodecomment
 n01   Profiles  --          default
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default:
     comment: profilecomment
 nodes:
@@ -208,8 +200,7 @@ NODE  IPMI IPADDR  IPMI PORT  IPMI USERNAME  IPMI INTERFACE
 ----  -----------  ---------  -------------  --------------
 n01   <nil>        --         admin          --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default:
     ipmi:
       username: admin
@@ -228,8 +219,7 @@ NODE  IPMI IPADDR  IPMI PORT  IPMI USERNAME  IPMI INTERFACE
 ----  -----------  ---------  -------------  --------------
 n01   <nil>        --         user           --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   default:
     ipmi:
       username: admin
@@ -250,8 +240,7 @@ NODE NAME  PROFILES  NETWORK
 ---------  --------  -------
 n01        [p1 p2]   --
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   p1: {}
   p2: {}
 nodes:
@@ -270,8 +259,7 @@ NODE  FIELD     PROFILE  VALUE
 ----  -----     -------  -----
 n01   Profiles  --       p1,p2
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   p1: {}
   p2: {}
 nodes:
@@ -290,8 +278,7 @@ NODE NAME  KERNEL OVERRIDE  CONTAINER  OVERLAYS (S/R)
 ---------  ---------------  ---------  --------------
 n01        --               --         /rop1,rop2
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   p1:
     runtime overlay:
     - rop1
@@ -311,8 +298,7 @@ NODE NAME  KERNEL OVERRIDE  CONTAINER  OVERLAYS (S/R)
 ---------  ---------------  ---------  --------------
 n01        --               --         sop1/nop1,~rop1,rop1,rop2
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   p1:
     system overlay:
     - sop1
@@ -339,8 +325,7 @@ n01   Profiles        --       p1
 n01   RuntimeOverlay  p1+      nop1,~rop1,rop1,rop2
 n01   SystemOverlay   p1       sop1
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   p1:
     system overlay:
     - sop1
@@ -366,8 +351,7 @@ NODE  FIELD           PROFILE  VALUE
 n01   Profiles        --       p1
 n01   RuntimeOverlay  p1+      nop1,rop1,rop2
 `,
-			inDb: `WW_INTERNAL: 45
-nodeprofiles:
+			inDb: `nodeprofiles:
   p1:
     runtime overlay:
     - rop1
@@ -389,8 +373,7 @@ NODE  FIELD                    PROFILE  VALUE
 ----  -----                    -------  -----
 n1    NetDevs[default].OnBoot  --       true
 `,
-			inDb: `WW_INTERNAL: 45
-nodes:
+			inDb: `nodes:
   n1:
     network devices:
       default:
@@ -405,8 +388,7 @@ nodes:
 NODE  FIELD  PROFILE  VALUE
 ----  -----  -------  -----
 `,
-			inDb: `WW_INTERNAL: 46
-nodes:
+			inDb: `nodes:
   wwnode1:
     network devices:
       default: {}
@@ -414,7 +396,7 @@ nodes:
 		},
 	}
 
-	conf_yml := `WW_INTERNAL: 0`
+	conf_yml := ``
 	tempWarewulfConf, warewulfConfErr := os.CreateTemp("", "warewulf.conf-")
 	assert.NoError(t, warewulfConfErr)
 	defer os.Remove(tempWarewulfConf.Name())
@@ -470,7 +452,7 @@ func TestListMultipleFormats(t *testing.T) {
   kernel: {}
   ipmi: {}
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
@@ -520,7 +502,7 @@ nodes:
   }
 ]
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
@@ -604,7 +586,7 @@ nodes:
   }
 ]
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
@@ -629,7 +611,7 @@ nodes:
   kernel: {}
   ipmi: {}
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
diff --git a/internal/app/wwctl/node/sensors/root_test.go b/internal/app/wwctl/node/sensors/root_test.go
index 3fff5f6a..450aab4c 100644
--- a/internal/app/wwctl/node/sensors/root_test.go
+++ b/internal/app/wwctl/node/sensors/root_test.go
@@ -15,7 +15,7 @@ func Test_Sensors(t *testing.T) {
 	warewulfd.SetNoDaemon()
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 43
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `
 nodeprofiles:
   default:
     ipmi:
diff --git a/internal/app/wwctl/node/set/main_test.go b/internal/app/wwctl/node/set/main_test.go
index 1c8fbc14..ba0f7a2f 100644
--- a/internal/app/wwctl/node/set/main_test.go
+++ b/internal/app/wwctl/node/set/main_test.go
@@ -56,16 +56,14 @@ func Test_Single_Node_Change_Profile(t *testing.T) {
 		args:    []string{"--profile=foo", "n01"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 45
-nodeprofiles:
+		inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
   n01:
     profiles:
     - default`,
-		outDb: `WW_INTERNAL: 45
-nodeprofiles:
+		outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -82,15 +80,13 @@ func Test_Node_Unset(t *testing.T) {
 		args:    []string{"--comment=UNDEF", "n01"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 43
-nodeprofiles: {}
+		inDB: `nodeprofiles: {}
 nodes:
   n01:
     comment: foo
     profiles:
     - default`,
-		outDb: `WW_INTERNAL: 43
-nodeprofiles: {}
+		outDb: `nodeprofiles: {}
 nodes:
   n01:
     profiles:
@@ -105,13 +101,11 @@ func Test_Set_Ipmi_Write_Explicit(t *testing.T) {
 		args:    []string{"--ipmiwrite", "true", "n01"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 43
-nodeprofiles: {}
+		inDB: `nodeprofiles: {}
 nodes:
   n01: {}
 `,
-		outDb: `WW_INTERNAL: 43
-nodeprofiles: {}
+		outDb: `nodeprofiles: {}
 nodes:
   n01:
     ipmi:
@@ -126,13 +120,11 @@ func Test_Set_Ipmi_Write_Implicit(t *testing.T) {
 		args:    []string{"--ipmiwrite", "n01"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 43
-nodeprofiles: {}
+		inDB: `nodeprofiles: {}
 nodes:
   n01: {}
 `,
-		outDb: `WW_INTERNAL: 43
-nodeprofiles: {}
+		outDb: `nodeprofiles: {}
 nodes:
   n01:
     ipmi:
@@ -147,15 +139,13 @@ func Test_Unset_Ipmi_Write(t *testing.T) {
 		args:    []string{"--ipmiwrite=UNDEF", "n01"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 43
-nodeprofiles: {}
+		inDB: `nodeprofiles: {}
 nodes:
   n01:
     ipmi:
       write: "true"
 `,
-		outDb: `WW_INTERNAL: 43
-nodeprofiles: {}
+		outDb: `nodeprofiles: {}
 nodes:
   n01: {}
 `,
@@ -168,15 +158,13 @@ func Test_Unset_Ipmi_Write_False(t *testing.T) {
 		args:    []string{"--ipmiwrite=UNDEF", "n01"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 43
-nodeprofiles: {}
+		inDB: `nodeprofiles: {}
 nodes:
   n01:
     ipmi:
       write: "false"
 `,
-		outDb: `WW_INTERNAL: 43
-nodeprofiles: {}
+		outDb: `nodeprofiles: {}
 nodes:
   n01: {}
 `,
@@ -189,8 +177,7 @@ func Test_Ipmi_Hidden_False(t *testing.T) {
 		args:    []string{"--ipmiwrite=false", "n01"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 43
-nodeprofiles:
+		inDB: `nodeprofiles:
   default:
     ipmi:
       write: "true"
@@ -199,8 +186,7 @@ nodes:
     profiles:
     - default
 `,
-		outDb: `WW_INTERNAL: 43
-nodeprofiles:
+		outDb: `nodeprofiles:
   default:
     ipmi:
       write: "true"
@@ -269,16 +255,14 @@ func Test_Multiple_Set_Tests(t *testing.T) {
 			args:    []string{"--profile=foo", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
   n01:
     profiles:
     - default`,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -292,8 +276,7 @@ nodes:
 			args:    []string{"--profile=foo", "n0[1-2]"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -303,8 +286,7 @@ nodes:
   n02:
     profiles:
     - default`,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -321,16 +303,14 @@ nodes:
 			args:    []string{"--ipmitagadd", "foo=baar", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
   n01:
     profiles:
     - default`,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -347,8 +327,7 @@ nodes:
 			args:    []string{"--tagdel", "tag1", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -358,8 +337,7 @@ nodes:
     tags:
       tag1: value1
       tag2: value2`,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -375,8 +353,7 @@ nodes:
 			args:    []string{"--fsname=var", "--fspath=/var", "--fsformat=btrfs", "--partname=var", "--partnumber=1", "--diskname=/dev/vda", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -384,8 +361,7 @@ nodes:
     profiles:
     - default
 `,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -408,8 +384,7 @@ nodes:
 			args:    []string{"--fsdel=foo", "n01"},
 			wantErr: true,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -427,8 +402,7 @@ nodes:
         format: btrfs
         path: /var
 `,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -451,8 +425,7 @@ nodes:
 			args:    []string{"--fsdel=/dev/disk/by-partlabel/var", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -470,8 +443,7 @@ nodes:
         format: btrfs
         path: /var
 `,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -490,8 +462,7 @@ nodes:
 			args:    []string{"--partdel=var", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -509,8 +480,7 @@ nodes:
         format: btrfs
         path: /var
 `,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -528,8 +498,7 @@ nodes:
 			args:    []string{"--diskdel=/dev/vda", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -546,8 +515,7 @@ nodes:
         format: btrfs
         path: /var
 `,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -565,16 +533,14 @@ nodes:
 			args:    []string{"--mtu", "1234", "--netname=mynet", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
 nodes:
   n01:
     profiles:
     - default`,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
 nodes:
@@ -591,8 +557,7 @@ nodes:
 			args:    []string{"--tagadd", "nodetag1=nodevalue1", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 45
-nodeprofiles:
+			inDB: `nodeprofiles:
   p1:
     comment: testit 1
     tags:
@@ -606,8 +571,7 @@ nodes:
     profiles:
     - p1
     - p2`,
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   p1:
     comment: testit 1
     tags:
@@ -630,13 +594,11 @@ nodes:
 			args:    []string{"n01", "--comment", "This is a , comment"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 43
-nodes:
+			inDB: `nodes:
   n01:
     comment: old comment
 `,
-			outDb: `WW_INTERNAL: 43
-nodeprofiles: {}
+			outDb: `nodeprofiles: {}
 nodes:
   n01:
     comment: This is a , comment
@@ -644,7 +606,7 @@ nodes:
 		},
 	}
 
-	conf_yml := `WW_INTERNAL: 0`
+	conf_yml := ``
 	tempWarewulfConf, warewulfConfErr := os.CreateTemp("", "warewulf.conf-")
 	assert.NoError(t, warewulfConfErr)
 	defer os.Remove(tempWarewulfConf.Name())
@@ -669,8 +631,7 @@ func Test_Node_Add(t *testing.T) {
 			args:    []string{"--tagadd=email=node", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 43
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
     tags:
@@ -679,8 +640,7 @@ nodes:
   n01:
     profiles:
     - default`,
-			outDb: `WW_INTERNAL: 43
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
     tags:
@@ -697,8 +657,7 @@ nodes:
 			args:    []string{"--tagadd=newtag=newval", "n01"},
 			wantErr: false,
 			stdout:  "",
-			inDB: `WW_INTERNAL: 43
-nodeprofiles:
+			inDB: `nodeprofiles:
   default:
     comment: testit
     tags:
@@ -709,8 +668,7 @@ nodes:
     - default
     tags:
       email: node`,
-			outDb: `WW_INTERNAL: 43
-nodeprofiles:
+			outDb: `nodeprofiles:
   default:
     comment: testit
     tags:
diff --git a/internal/app/wwctl/node/set/root.go b/internal/app/wwctl/node/set/root.go
index 3e016e2a..6821614d 100644
--- a/internal/app/wwctl/node/set/root.go
+++ b/internal/app/wwctl/node/set/root.go
@@ -14,7 +14,7 @@ type variables struct {
 	setNodeAll bool
 	setYes     bool
 	setForce   bool
-	nodeConf   node.NodeConf
+	nodeConf   node.Node
 	nodeDel    node.NodeConfDel
 	nodeAdd    node.NodeConfAdd
 }
diff --git a/internal/app/wwctl/overlay/build/main.go b/internal/app/wwctl/overlay/build/main.go
index 5f347bc6..819d08df 100644
--- a/internal/app/wwctl/overlay/build/main.go
+++ b/internal/app/wwctl/overlay/build/main.go
@@ -71,7 +71,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 
 	}
 
-	if BuildHost && controller.Warewulf.EnableHostOverlay {
+	if BuildHost && controller.Warewulf.EnableHostOverlay() {
 		err := overlay.BuildHostOverlay()
 		if err != nil {
 			return fmt.Errorf("host overlay could not be built: %s", err)
diff --git a/internal/app/wwctl/overlay/imprt/main.go b/internal/app/wwctl/overlay/imprt/main.go
index 190747ce..acad75ec 100644
--- a/internal/app/wwctl/overlay/imprt/main.go
+++ b/internal/app/wwctl/overlay/imprt/main.go
@@ -72,7 +72,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 			return fmt.Errorf("could not get node list: %s", err)
 		}
 
-		var updateNodes []node.NodeConf
+		var updateNodes []node.Node
 
 		for _, node := range nodes {
 			if util.InSlice(node.SystemOverlay, overlayName) {
diff --git a/internal/app/wwctl/overlay/imprt/main_test.go b/internal/app/wwctl/overlay/imprt/main_test.go
index 8d8ef486..b78ea764 100644
--- a/internal/app/wwctl/overlay/imprt/main_test.go
+++ b/internal/app/wwctl/overlay/imprt/main_test.go
@@ -45,14 +45,11 @@ func Test_List(t *testing.T) {
 		t.FailNow()
 	}
 
-	inDb := `WW_INTERNAL: 45
-nodeprofiles:
+	inDb := `nodeprofiles:
   default: {}
 nodes: {}
 `
-	conf_yml := `
-WW_INTERNAL: 0
-    `
+	conf_yml := ``
 
 	conf := warewulfconf.New()
 	err = conf.Parse([]byte(conf_yml))
diff --git a/internal/app/wwctl/overlay/show/main_test.go b/internal/app/wwctl/overlay/show/main_test.go
index 451feb0a..e341b644 100644
--- a/internal/app/wwctl/overlay/show/main_test.go
+++ b/internal/app/wwctl/overlay/show/main_test.go
@@ -23,8 +23,7 @@ overlay name {{ .Overlay }}
 
 func Test_Overlay_List(t *testing.T) {
 	env := testenv.New(t)
-	env.WriteFile(t, "etc/warewulf/warewulf.conf", `WW_INTERNAL: 43
-ipaddr: 192.168.0.1/24
+	env.WriteFile(t, "etc/warewulf/warewulf.conf", `ipaddr: 192.168.0.1/24
 netmask: 255.255.255.0
 network: 192.168.0.0
 warewulf:
@@ -53,8 +52,7 @@ nfs:
     mount: false`)
 
 	env.WriteFile(t, "etc/warewulf/nodes.conf",
-		`WW_INTERNAL: 45
-nodeprofiles:
+		`nodeprofiles:
   default:
     tags:
       email: admin@localhost
@@ -141,8 +139,7 @@ func TestShowServerTemplate(t *testing.T) {
 
 	env := testenv.New(t)
 	env.WriteFile(t, "etc/warewulf/nodes.conf",
-		`WW_INTERNAL: 45
-nodeprofiles:
+		`nodeprofiles:
   default:
     tags:
       email: admin@localhost
diff --git a/internal/app/wwctl/power/cycle/root_test.go b/internal/app/wwctl/power/cycle/root_test.go
index 89ba118c..9e20db8f 100644
--- a/internal/app/wwctl/power/cycle/root_test.go
+++ b/internal/app/wwctl/power/cycle/root_test.go
@@ -15,7 +15,7 @@ func Test_PowerCycle(t *testing.T) {
 	warewulfd.SetNoDaemon()
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 43
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `
 nodeprofiles:
   default:
     ipmi:
diff --git a/internal/app/wwctl/power/off/root_test.go b/internal/app/wwctl/power/off/root_test.go
index 4dd31141..5dc368c8 100644
--- a/internal/app/wwctl/power/off/root_test.go
+++ b/internal/app/wwctl/power/off/root_test.go
@@ -15,7 +15,7 @@ func Test_Power_Status(t *testing.T) {
 	warewulfd.SetNoDaemon()
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 43
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `
 nodeprofiles:
   default:
     ipmi:
diff --git a/internal/app/wwctl/power/on/root_test.go b/internal/app/wwctl/power/on/root_test.go
index 82485f10..8ea62f84 100644
--- a/internal/app/wwctl/power/on/root_test.go
+++ b/internal/app/wwctl/power/on/root_test.go
@@ -15,7 +15,7 @@ func Test_Power_Status(t *testing.T) {
 	warewulfd.SetNoDaemon()
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 43
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `
 nodeprofiles:
   default:
     ipmi:
diff --git a/internal/app/wwctl/power/reset/root_test.go b/internal/app/wwctl/power/reset/root_test.go
index 131f831a..8c9a0629 100644
--- a/internal/app/wwctl/power/reset/root_test.go
+++ b/internal/app/wwctl/power/reset/root_test.go
@@ -15,7 +15,7 @@ func Test_Power_Status(t *testing.T) {
 	warewulfd.SetNoDaemon()
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 43
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `
 nodeprofiles:
   default:
     ipmi:
diff --git a/internal/app/wwctl/power/soft/root_test.go b/internal/app/wwctl/power/soft/root_test.go
index 14728692..565f2d07 100644
--- a/internal/app/wwctl/power/soft/root_test.go
+++ b/internal/app/wwctl/power/soft/root_test.go
@@ -15,7 +15,7 @@ func Test_Power_Status(t *testing.T) {
 	warewulfd.SetNoDaemon()
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 43
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `
 nodeprofiles:
   default:
     ipmi:
diff --git a/internal/app/wwctl/power/status/root_test.go b/internal/app/wwctl/power/status/root_test.go
index e7160e3e..998dee14 100644
--- a/internal/app/wwctl/power/status/root_test.go
+++ b/internal/app/wwctl/power/status/root_test.go
@@ -15,7 +15,7 @@ func Test_Power_Status(t *testing.T) {
 	warewulfd.SetNoDaemon()
 	env := testenv.New(t)
 	defer env.RemoveAll(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 43
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `
 nodeprofiles:
   default:
     ipmi:
diff --git a/internal/app/wwctl/profile/add/main_test.go b/internal/app/wwctl/profile/add/main_test.go
index d44f3c68..d0c3fb4a 100644
--- a/internal/app/wwctl/profile/add/main_test.go
+++ b/internal/app/wwctl/profile/add/main_test.go
@@ -20,22 +20,20 @@ func Test_Add(t *testing.T) {
 	}{
 		{
 			name:    "single profile add",
-			args:    []string{"--yes", "p01"},
+			args:    []string{"p01"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   p01: {}
 nodes: {}
 `,
 		},
 		{
 			name:    "single profile add with netname and netdev",
-			args:    []string{"--yes", "--netname", "primary", "--netdev", "eno3", "p02"},
+			args:    []string{"--netname", "primary", "--netdev", "eno3", "p02"},
 			wantErr: false,
 			stdout:  "",
-			outDb: `WW_INTERNAL: 45
-nodeprofiles:
+			outDb: `nodeprofiles:
   p02:
     network devices:
       primary:
@@ -48,8 +46,7 @@ nodes: {}
 	warewulfd.SetNoDaemon()
 	for _, tt := range tests {
 		env := testenv.New(t)
-		env.WriteFile(t, "etc/warewulf/nodes.conf",
-			`WW_INTERNAL: 45`)
+		env.WriteFile(t, "etc/warewulf/nodes.conf", ``)
 		var err error
 		t.Run(tt.name, func(t *testing.T) {
 			baseCmd := GetCommand()
diff --git a/internal/app/wwctl/profile/add/root.go b/internal/app/wwctl/profile/add/root.go
index f55eb7f8..cb9d30af 100644
--- a/internal/app/wwctl/profile/add/root.go
+++ b/internal/app/wwctl/profile/add/root.go
@@ -11,12 +11,8 @@ import (
 )
 
 type variables struct {
-	profileConf  node.ProfileConf
-	nodeAdd      node.NodeConfAdd
-	SetNetDevDel string
-	SetNodeAll   bool
-	SetYes       bool
-	SetForce     bool
+	profileConf node.Profile
+	nodeAdd     node.NodeConfAdd
 }
 
 // GetRootCommand returns the root cobra.Command for the application.
@@ -59,6 +55,5 @@ func GetCommand() *cobra.Command {
 	}); err != nil {
 		log.Println(err)
 	}
-	baseCmd.PersistentFlags().BoolVarP(&vars.SetYes, "yes", "y", false, "Set 'yes' to all questions asked")
 	return baseCmd
 }
diff --git a/internal/app/wwctl/profile/edit/main.go b/internal/app/wwctl/profile/edit/main.go
index c3ec9437..f981ada4 100644
--- a/internal/app/wwctl/profile/edit/main.go
+++ b/internal/app/wwctl/profile/edit/main.go
@@ -39,7 +39,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		Output: args,
 	}
 	profileListMsg := apiprofile.FilteredProfiles(&filterList)
-	profileMap := make(map[string]*node.ProfileConf)
+	profileMap := make(map[string]*node.Profile)
 	// got proper yaml back
 	_ = yaml.Unmarshal([]byte(profileListMsg.NodeConfMapYaml), profileMap)
 	file, err := os.CreateTemp(os.TempDir(), "ww4ProfileEdit*.yaml")
@@ -51,7 +51,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		_ = file.Truncate(0)
 		_, _ = file.Seek(0, 0)
 		if !NoHeader {
-			yamlTemplate := node.UnmarshalConf(node.ProfileConf{}, []string{"tagsdel"})
+			yamlTemplate := node.UnmarshalConf(node.Profile{}, []string{"tagsdel"})
 			_, _ = file.WriteString("#profilename:\n#  " + strings.Join(yamlTemplate, "\n#  ") + "\n")
 		}
 		_, _ = file.WriteString(profileListMsg.NodeConfMapYaml)
@@ -74,7 +74,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		wwlog.Debug("Hashes are before %s and after %s\n", sum1, sum2)
 		if sum1 != sum2 {
 			wwlog.Debug("Profiles were modified")
-			modifiedProfileMap := make(map[string]*node.ProfileConf)
+			modifiedProfileMap := make(map[string]*node.Profile)
 			_, _ = file.Seek(0, 0)
 			// ignore error as only may occurs under strange circumstances
 			buffer, _ := io.ReadAll(file)
diff --git a/internal/app/wwctl/profile/list/main_test.go b/internal/app/wwctl/profile/list/main_test.go
index 39362f5d..da7e6a0a 100644
--- a/internal/app/wwctl/profile/list/main_test.go
+++ b/internal/app/wwctl/profile/list/main_test.go
@@ -29,7 +29,7 @@ PROFILE NAME  COMMENT/DESCRIPTION
 ------------  -------------------
 default       --
 `,
-			inDb: `WW_INTERNAL: 45
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
@@ -47,7 +47,7 @@ PROFILE NAME  COMMENT/DESCRIPTION
 default       --
 test          --
 `,
-			inDb: `WW_INTERNAL: 45
+			inDb: `
 nodeprofiles:
   default: {}
   test: {}
@@ -65,7 +65,7 @@ PROFILE NAME  COMMENT/DESCRIPTION
 ------------  -------------------
 test          --
 `,
-			inDb: `WW_INTERNAL: 45
+			inDb: `
 nodeprofiles:
   default: {}
   test: {}
@@ -84,7 +84,7 @@ PROFILE NAME  COMMENT/DESCRIPTION
 default       --
 test          --
 `,
-			inDb: `WW_INTERNAL: 45
+			inDb: `
 nodeprofiles:
   default: {}
   test: {}
@@ -96,7 +96,7 @@ nodes:
 		},
 	}
 
-	conf_yml := `WW_INTERNAL: 0`
+	conf_yml := ``
 	tempWarewulfConf, warewulfConfErr := os.CreateTemp("", "warewulf.conf-")
 	assert.NoError(t, warewulfConfErr)
 	defer os.Remove(tempWarewulfConf.Name())
@@ -158,7 +158,7 @@ func TestListMultipleFormats(t *testing.T) {
 			name:   "single profile list yaml output",
 			args:   []string{"-y"},
 			output: `default: {}`,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
@@ -191,7 +191,7 @@ nodes:
   }
 }
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
 nodes:
@@ -207,7 +207,7 @@ nodes:
 default: {}
 test: {}
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
   test: {}
@@ -258,7 +258,7 @@ nodes:
   }
 }
 `,
-			inDb: `WW_INTERNAL: 43
+			inDb: `
 nodeprofiles:
   default: {}
   test: {}
@@ -270,7 +270,7 @@ nodes:
 		},
 	}
 
-	conf_yml := `WW_INTERNAL: 0`
+	conf_yml := ``
 	tempWarewulfConf, warewulfConfErr := os.CreateTemp("", "warewulf.conf-")
 	assert.NoError(t, warewulfConfErr)
 	defer os.Remove(tempWarewulfConf.Name())
diff --git a/internal/app/wwctl/profile/set/main_test.go b/internal/app/wwctl/profile/set/main_test.go
index 538d6f0b..ef677dd3 100644
--- a/internal/app/wwctl/profile/set/main_test.go
+++ b/internal/app/wwctl/profile/set/main_test.go
@@ -54,13 +54,11 @@ func Test_Set_Netdev(t *testing.T) {
 		args:    []string{"--netname=default", "--netdev=eth0", "default"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 45
-nodeprofiles:
+		inDB: `nodeprofiles:
   default: {}
 nodes: {}
 `,
-		outDb: `WW_INTERNAL: 45
-nodeprofiles:
+		outDb: `nodeprofiles:
   default:
     network devices:
       default:
@@ -74,13 +72,11 @@ func Test_Set_Netdev_and_Mask(t *testing.T) {
 		args:    []string{"--netname=default", "--netdev=eth0", "-M=255.255.255.0", "default"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 45
-nodeprofiles:
+		inDB: `nodeprofiles:
   default: {}
 nodes: {}
 `,
-		outDb: `WW_INTERNAL: 45
-nodeprofiles:
+		outDb: `nodeprofiles:
   default:
     network devices:
       default:
@@ -96,16 +92,14 @@ func Test_Set_Mask_Existing_NetDev(t *testing.T) {
 		args:    []string{"--netname=default", "-M=255.255.255.0", "default"},
 		wantErr: false,
 		stdout:  "",
-		inDB: `WW_INTERNAL: 45
-nodeprofiles:
+		inDB: `nodeprofiles:
   default:
     network devices:
       default:
         device: eth0
 nodes: {}
 `,
-		outDb: `WW_INTERNAL: 45
-nodeprofiles:
+		outDb: `nodeprofiles:
   default:
     network devices:
       default:
diff --git a/internal/app/wwctl/profile/set/root.go b/internal/app/wwctl/profile/set/root.go
index 332fd0d5..b341bfd3 100644
--- a/internal/app/wwctl/profile/set/root.go
+++ b/internal/app/wwctl/profile/set/root.go
@@ -21,7 +21,7 @@ type variables struct {
 	partName     string
 	diskName     string
 	fsName       string
-	profileConf  node.ProfileConf
+	profileConf  node.Profile
 	profileDel   node.NodeConfDel
 	profileAdd   node.NodeConfAdd
 }
diff --git a/internal/app/wwctl/root.go b/internal/app/wwctl/root.go
index fb730d48..d225e7df 100644
--- a/internal/app/wwctl/root.go
+++ b/internal/app/wwctl/root.go
@@ -15,6 +15,7 @@ import (
 	"github.com/warewulf/warewulf/internal/app/wwctl/profile"
 	"github.com/warewulf/warewulf/internal/app/wwctl/server"
 	"github.com/warewulf/warewulf/internal/app/wwctl/ssh"
+	"github.com/warewulf/warewulf/internal/app/wwctl/upgrade"
 	"github.com/warewulf/warewulf/internal/app/wwctl/version"
 	warewulfconf "github.com/warewulf/warewulf/internal/pkg/config"
 	"github.com/warewulf/warewulf/internal/pkg/help"
@@ -60,6 +61,7 @@ func init() {
 	rootCmd.AddCommand(ssh.GetCommand())
 	rootCmd.AddCommand(genconf.GetCommand())
 	rootCmd.AddCommand(clean.GetCommand())
+	rootCmd.AddCommand(upgrade.Command)
 }
 
 // GetRootCommand returns the root cobra.Command for the application.
@@ -89,7 +91,7 @@ func rootPersistentPreRunE(cmd *cobra.Command, args []string) (err error) {
 		}
 	}
 	if err != nil {
-		wwlog.Error("version: %s relase: %s WW_INTERNAL: %s", warewulfconf.Version, warewulfconf.Release, warewulfconf.Confversion)
+		wwlog.Error("version: %s relase: %s", warewulfconf.Version, warewulfconf.Release)
 		return
 	}
 	err = conf.SetDynamicDefaults()
diff --git a/internal/app/wwctl/upgrade/cobra.go b/internal/app/wwctl/upgrade/cobra.go
new file mode 100644
index 00000000..88e1a611
--- /dev/null
+++ b/internal/app/wwctl/upgrade/cobra.go
@@ -0,0 +1,23 @@
+package upgrade
+
+import (
+	"github.com/spf13/cobra"
+
+	"github.com/warewulf/warewulf/internal/app/wwctl/upgrade/config"
+	"github.com/warewulf/warewulf/internal/app/wwctl/upgrade/nodes"
+)
+
+var (
+	Command = &cobra.Command{
+		DisableFlagsInUseLine: true,
+		Use:                   "upgrade <config|nodes> [OPTIONS]",
+		Short:                 "Upgrade configuration files",
+		Long: `Upgrade warewulf.conf or nodes.conf from a previous version of Warewulf 4 to a format
+supported by the current version.`,
+	}
+)
+
+func init() {
+	Command.AddCommand(config.Command)
+	Command.AddCommand(nodes.Command)
+}
diff --git a/internal/app/wwctl/upgrade/config/cobra.go b/internal/app/wwctl/upgrade/config/cobra.go
new file mode 100644
index 00000000..a660a32f
--- /dev/null
+++ b/internal/app/wwctl/upgrade/config/cobra.go
@@ -0,0 +1,56 @@
+package config
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/warewulf/warewulf/internal/pkg/config"
+	libupgrade "github.com/warewulf/warewulf/internal/pkg/upgrade"
+	"github.com/warewulf/warewulf/internal/pkg/util"
+)
+
+var (
+	Command = &cobra.Command{
+		DisableFlagsInUseLine: true,
+		Use:                   "config [OPTIONS]",
+		Short:                 "Upgrade an existing nodes.conf",
+		Long: `Upgrades nodes.conf from a previous version of Warewulf 4 to a format
+supported by the current version.`,
+		RunE: UpgradeNodesConf,
+	}
+
+	inputPath  string
+	outputPath string
+)
+
+func init() {
+	Command.Flags().StringVarP(&inputPath, "input-path", "i", config.ConfigFile, "Path to a legacy nodes.conf")
+	Command.Flags().StringVarP(&outputPath, "output-path", "o", config.ConfigFile, "Path to write the upgraded nodes.conf to")
+}
+
+func UpgradeNodesConf(cmd *cobra.Command, args []string) error {
+	data, err := os.ReadFile(inputPath)
+	if err != nil {
+		return err
+	}
+	legacy, err := libupgrade.ParseConfig(data)
+	if err != nil {
+		return err
+	}
+	upgraded := legacy.Upgrade()
+	if outputPath == "-" {
+		upgradedYaml, err := upgraded.Dump()
+		if err != nil {
+			return err
+		}
+		fmt.Print(string(upgradedYaml))
+		return nil
+	} else {
+		if err := util.CopyFile(outputPath, outputPath+"-old"); err != nil {
+			return err
+		}
+		return upgraded.PersistToFile(outputPath)
+	}
+}
diff --git a/internal/app/wwctl/upgrade/nodes/cobra.go b/internal/app/wwctl/upgrade/nodes/cobra.go
new file mode 100644
index 00000000..b652562b
--- /dev/null
+++ b/internal/app/wwctl/upgrade/nodes/cobra.go
@@ -0,0 +1,66 @@
+package nodes
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/warewulf/warewulf/internal/pkg/node"
+	libupgrade "github.com/warewulf/warewulf/internal/pkg/upgrade"
+	"github.com/warewulf/warewulf/internal/pkg/util"
+)
+
+var (
+	Command = &cobra.Command{
+		DisableFlagsInUseLine: true,
+		Use:                   "nodes [OPTIONS]",
+		Short:                 "Upgrade an existing nodes.conf",
+		Long: `Upgrades nodes.conf from a previous version of Warewulf 4 to a format
+supported by the current version.`,
+		RunE: UpgradeNodesConf,
+	}
+
+	addDefaults     bool
+	replaceOverlays bool
+	inputPath       string
+	outputPath      string
+)
+
+func init() {
+	Command.Flags().BoolVar(&addDefaults, "add-defaults", false, "Configure a default profile and set default node values")
+	Command.Flags().BoolVar(&replaceOverlays, "replace-overlays", false, "Replace 'wwinit' and 'generic' overlays with their split replacements")
+	Command.Flags().StringVarP(&inputPath, "input-path", "i", node.ConfigFile, "Path to a legacy nodes.conf")
+	Command.Flags().StringVarP(&outputPath, "output-path", "o", node.ConfigFile, "Path to write the upgraded nodes.conf to")
+	if err := Command.MarkFlagRequired("add-defaults"); err != nil {
+		panic(err)
+	}
+	if err := Command.MarkFlagRequired("replace-overlays"); err != nil {
+		panic(err)
+	}
+}
+
+func UpgradeNodesConf(cmd *cobra.Command, args []string) error {
+	data, err := os.ReadFile(inputPath)
+	if err != nil {
+		return err
+	}
+	legacy, err := libupgrade.ParseNodes(data)
+	if err != nil {
+		return err
+	}
+	upgraded := legacy.Upgrade(addDefaults, replaceOverlays)
+	if outputPath == "-" {
+		upgradedYaml, err := upgraded.Dump()
+		if err != nil {
+			return err
+		}
+		fmt.Print(string(upgradedYaml))
+		return nil
+	} else {
+		if err := util.CopyFile(outputPath, outputPath+"-old"); err != nil {
+			return err
+		}
+		return upgraded.PersistToFile(outputPath)
+	}
+}
diff --git a/internal/pkg/api/container/container.go b/internal/pkg/api/container/container.go
index c9cc97e8..92618180 100644
--- a/internal/pkg/api/container/container.go
+++ b/internal/pkg/api/container/container.go
@@ -82,7 +82,7 @@ func ContainerBuild(cbp *wwapiv1.ContainerBuildParameter) (err error) {
 		if len(containers) != 1 {
 			return fmt.Errorf("can only set default for one container")
 		} else {
-			var nodeDB node.NodeYaml
+			var nodeDB node.NodesYaml
 			nodeDB, err = node.New()
 			if err != nil {
 				return fmt.Errorf("could not open node configuration: %s", err)
@@ -238,7 +238,7 @@ func ContainerImport(cip *wwapiv1.ContainerImportParameter) (containerName strin
 	}
 
 	if cip.Default {
-		var nodeDB node.NodeYaml
+		var nodeDB node.NodesYaml
 		nodeDB, err = node.New()
 		if err != nil {
 			err = fmt.Errorf("could not open node configuration: %s", err.Error())
diff --git a/internal/pkg/api/node/delete.go b/internal/pkg/api/node/delete.go
index 7128c2bc..41e60917 100644
--- a/internal/pkg/api/node/delete.go
+++ b/internal/pkg/api/node/delete.go
@@ -15,7 +15,7 @@ import (
 // NodeDelete adds nodes for management by Warewulf.
 func NodeDelete(ndp *wwapiv1.NodeDeleteParameter) (err error) {
 
-	var nodeList []node.NodeConf
+	var nodeList []node.Node
 	nodeList, err = NodeDeleteParameterCheck(ndp, false)
 	if err != nil {
 		return
@@ -55,7 +55,7 @@ func NodeDelete(ndp *wwapiv1.NodeDeleteParameter) (err error) {
 // NodeDeleteParameterCheck does error checking on NodeDeleteParameter.
 // Output to the console if console is true.
 // Returns the nodes to delete.
-func NodeDeleteParameterCheck(ndp *wwapiv1.NodeDeleteParameter, console bool) (nodeList []node.NodeConf, err error) {
+func NodeDeleteParameterCheck(ndp *wwapiv1.NodeDeleteParameter, console bool) (nodeList []node.Node, err error) {
 
 	if ndp == nil {
 		err = fmt.Errorf("NodeDeleteParameter is nil")
diff --git a/internal/pkg/api/node/edit.go b/internal/pkg/api/node/edit.go
index 79324c59..dc988bde 100644
--- a/internal/pkg/api/node/edit.go
+++ b/internal/pkg/api/node/edit.go
@@ -37,7 +37,7 @@ func NodeAddFromYaml(nodeList *wwapiv1.NodeYaml) (err error) {
 	if err != nil {
 		return fmt.Errorf("could not open NodeDB: %w", err)
 	}
-	nodeMap := make(map[string]*node.NodeConf)
+	nodeMap := make(map[string]*node.Node)
 	err = yaml.Unmarshal([]byte(nodeList.NodeConfMapYaml), nodeMap)
 	if err != nil {
 		return fmt.Errorf("could not unmarshal Yaml: %w", err)
diff --git a/internal/pkg/api/node/set.go b/internal/pkg/api/node/set.go
index e6f4c142..3dff91aa 100644
--- a/internal/pkg/api/node/set.go
+++ b/internal/pkg/api/node/set.go
@@ -17,7 +17,7 @@ func NodeSet(set *wwapiv1.ConfSetParameter) (err error) {
 	if set == nil {
 		return fmt.Errorf("NodeSetParameter is nil")
 	}
-	var nodeDB node.NodeYaml
+	var nodeDB node.NodesYaml
 	nodeDB, _, err = NodeSetParameterCheck(set)
 	if err != nil {
 		return err
@@ -35,7 +35,7 @@ func NodeSet(set *wwapiv1.ConfSetParameter) (err error) {
 NodeSetParameterCheck does error checking and returns a modified
 NodeYml which than can be persisted
 */
-func NodeSetParameterCheck(set *wwapiv1.ConfSetParameter) (nodeDB node.NodeYaml, count uint, err error) {
+func NodeSetParameterCheck(set *wwapiv1.ConfSetParameter) (nodeDB node.NodesYaml, count uint, err error) {
 	nodeDB, err = node.New()
 	if err != nil {
 		wwlog.Error("Could not open configuration: %s", err)
@@ -60,7 +60,7 @@ func NodeSetParameterCheck(set *wwapiv1.ConfSetParameter) (nodeDB node.NodeYaml,
 	for _, nId := range set.ConfList {
 		if util.InSlice(set.ConfList, nId) {
 			wwlog.Debug("evaluating node: %s", nId)
-			var nodePtr *node.NodeConf
+			var nodePtr *node.Node
 			nodePtr, err = nodeDB.GetNodeOnlyPtr(nId)
 			if err != nil {
 				wwlog.Warn("invalid node: %s", nId)
diff --git a/internal/pkg/api/profile/delete.go b/internal/pkg/api/profile/delete.go
index d0dc4cc4..b219da33 100644
--- a/internal/pkg/api/profile/delete.go
+++ b/internal/pkg/api/profile/delete.go
@@ -40,7 +40,7 @@ func ProfileDelete(ndp *wwapiv1.NodeDeleteParameter) (err error) {
 // ProfileDeleteParameterCheck does error checking on ProfileDeleteParameter.
 // Output to the console if console is true.
 // Returns the profiles to delete.
-func ProfileDeleteParameterCheck(ndp *wwapiv1.NodeDeleteParameter, console bool) (nodeDB node.NodeYaml, profileList []string, err error) {
+func ProfileDeleteParameterCheck(ndp *wwapiv1.NodeDeleteParameter, console bool) (nodeDB node.NodesYaml, profileList []string, err error) {
 
 	if ndp == nil {
 		err = fmt.Errorf("profileDeleteParameter is nil")
diff --git a/internal/pkg/api/profile/edit.go b/internal/pkg/api/profile/edit.go
index 059a3272..c8a384a0 100644
--- a/internal/pkg/api/profile/edit.go
+++ b/internal/pkg/api/profile/edit.go
@@ -40,7 +40,7 @@ func ProfileAddFromYaml(nodeList *wwapiv1.NodeAddParameter) (err error) {
 		return fmt.Errorf("got wrong hash, not modifying profile database")
 	}
 
-	profileMap := make(map[string]*node.ProfileConf)
+	profileMap := make(map[string]*node.Profile)
 	err = yaml.Unmarshal([]byte(nodeList.NodeConfYaml), profileMap)
 	if err != nil {
 		return fmt.Errorf("couldn't unmarshall Yaml: %w", err)
diff --git a/internal/pkg/api/profile/list.go b/internal/pkg/api/profile/list.go
index 5d027943..be8073eb 100644
--- a/internal/pkg/api/profile/list.go
+++ b/internal/pkg/api/profile/list.go
@@ -38,7 +38,7 @@ func ProfileList(ShowOpt *wwapiv1.GetProfileList) (profileList wwapiv1.ProfileLi
 			}
 		}
 	} else if ShowOpt.ShowYaml {
-		profileMap := make(map[string]node.ProfileConf)
+		profileMap := make(map[string]node.Profile)
 		for _, profile := range profiles {
 			profileMap[profile.Id()] = profile
 		}
@@ -46,7 +46,7 @@ func ProfileList(ShowOpt *wwapiv1.GetProfileList) (profileList wwapiv1.ProfileLi
 		buf, _ := yaml.Marshal(profileMap)
 		profileList.Output = append(profileList.Output, string(buf))
 	} else if ShowOpt.ShowJson {
-		profileMap := make(map[string]node.ProfileConf)
+		profileMap := make(map[string]node.Profile)
 		for _, profile := range profiles {
 			profileMap[profile.Id()] = profile
 		}
diff --git a/internal/pkg/api/profile/set.go b/internal/pkg/api/profile/set.go
index 97c25c51..e20cd55c 100644
--- a/internal/pkg/api/profile/set.go
+++ b/internal/pkg/api/profile/set.go
@@ -35,7 +35,7 @@ func ProfileSet(set *wwapiv1.ConfSetParameter) (err error) {
 NodeSetParameterCheck does error checking and returns a modified
 NodeYml which than can be persisted
 */
-func ProfileSetParameterCheck(set *wwapiv1.ConfSetParameter) (nodeDB node.NodeYaml, count uint, err error) {
+func ProfileSetParameterCheck(set *wwapiv1.ConfSetParameter) (nodeDB node.NodesYaml, count uint, err error) {
 	nodeDB, err = node.New()
 	if err != nil {
 		wwlog.Error("Could not open configuration: %s", err)
@@ -60,7 +60,7 @@ func ProfileSetParameterCheck(set *wwapiv1.ConfSetParameter) (nodeDB node.NodeYa
 	for _, profileId := range set.ConfList {
 		if util.InSlice(set.ConfList, profileId) {
 			wwlog.Verbose("evaluating profile: %s", profileId)
-			var profilePtr *node.ProfileConf
+			var profilePtr *node.Profile
 			profilePtr, err = nodeDB.GetProfilePtr(profileId)
 			if err != nil {
 				wwlog.Warn("invalid profile: %s", profileId)
diff --git a/internal/pkg/config/buildconfig.go.in b/internal/pkg/config/buildconfig.go.in
index 560afccd..d92a5128 100644
--- a/internal/pkg/config/buildconfig.go.in
+++ b/internal/pkg/config/buildconfig.go.in
@@ -2,6 +2,8 @@ package config
 
 import (
 	"path"
+
+	"github.com/warewulf/warewulf/internal/pkg/util"
 )
 
 var ConfigFile = "@SYSCONFDIR@/warewulf/warewulf.conf"
@@ -24,28 +26,49 @@ type BuildConfig struct {
 const Version = "@VERSION@"
 const Release = "@RELEASE@"
 
-// must be set .in file so that its available for tests
-const Confversion = "45"
-
 type TFTPConf struct {
-	Enabled     bool   `yaml:"enabled" default:"true"`
-	TftpRoot    string `yaml:"tftproot" default:"@TFTPDIR@"`
-	SystemdName string `yaml:"systemd name" default:"tftp"`
+	EnabledP    *bool  `yaml:"enabled" default:"true"`
+	TftpRoot    string `yaml:"tftproot,omitempty" default:"@TFTPDIR@"`
+	SystemdName string `yaml:"systemd name,omitempty" default:"tftp"`
 
-	IpxeBinaries map[string]string `yaml:"ipxe" default:"{\"00:09\": \"ipxe-snponly-x86_64.efi\",\"00:00\": \"undionly.kpxe\",\"00:0B\": \"arm64-efi/snponly.efi\",\"00:07\":  \"ipxe-snponly-x86_64.efi\"}"`
+	IpxeBinaries map[string]string `yaml:"ipxe,omitempty" default:"{\"00:09\": \"ipxe-snponly-x86_64.efi\",\"00:00\": \"undionly.kpxe\",\"00:0B\": \"arm64-efi/snponly.efi\",\"00:07\":  \"ipxe-snponly-x86_64.efi\"}"`
+}
+
+func (this TFTPConf) Enabled() bool {
+	return util.BoolP(this.EnabledP)
 }
 
 // WarewulfConf adds additional Warewulf-specific configuration to
 // BaseConf.
 type WarewulfConf struct {
-	Port              int    `yaml:"port" default:"9873"`
-	Secure            bool   `yaml:"secure" default:"true"`
-	UpdateInterval    int    `yaml:"update interval" default:"60"`
-	AutobuildOverlays bool   `yaml:"autobuild overlays" default:"true"`
-	EnableHostOverlay bool   `yaml:"host overlay" default:"true"`
-	Syslog            bool   `yaml:"syslog" default:"false"`
-	DataStore         string `yaml:"datastore" default:"@DATADIR@"`
-	GrubBoot          bool   `yaml:"grubboot" default:"false"`
+	Port               int    `yaml:"port,omitempty" default:"9873"`
+	SecureP            *bool  `yaml:"secure,omitempty" default:"true"`
+	UpdateInterval     int    `yaml:"update interval,omitempty" default:"60"`
+	AutobuildOverlaysP *bool  `yaml:"autobuild overlays,omitempty" default:"true"`
+	EnableHostOverlayP *bool  `yaml:"host overlay,omitempty" default:"true"`
+	SyslogP            *bool  `yaml:"syslog,omitempty" default:"false"`
+	DataStore          string `yaml:"datastore,omitempty" default:"@DATADIR@"`
+	GrubBootP          *bool  `yaml:"grubboot,omitempty" default:"false"`
+}
+
+func (this WarewulfConf) Secure() bool {
+	return util.BoolP(this.SecureP)
+}
+
+func (this WarewulfConf) AutobuildOverlays() bool {
+	return util.BoolP(this.AutobuildOverlaysP)
+}
+
+func (this WarewulfConf) EnableHostOverlay() bool {
+	return util.BoolP(this.EnableHostOverlayP)
+}
+
+func (this WarewulfConf) Syslog() bool {
+	return util.BoolP(this.SyslogP)
+}
+
+func (this WarewulfConf) GrubBoot() bool {
+	return util.BoolP(this.GrubBootP)
 }
 
 func (paths BuildConfig) OciBlobCachedir() string {
diff --git a/internal/pkg/config/dhcp.go b/internal/pkg/config/dhcp.go
index b1b8790e..56c70986 100644
--- a/internal/pkg/config/dhcp.go
+++ b/internal/pkg/config/dhcp.go
@@ -1,11 +1,19 @@
 package config
 
+import (
+	"github.com/warewulf/warewulf/internal/pkg/util"
+)
+
 // DHCPConf represents the configuration for the DHCP service that
 // Warewulf will configure.
 type DHCPConf struct {
-	Enabled     bool   `yaml:"enabled" default:"true"`
-	Template    string `yaml:"template" default:"default"`
+	EnabledP    *bool  `yaml:"enabled,omitempty" default:"true"`
+	Template    string `yaml:"template,omitempty" default:"default"`
 	RangeStart  string `yaml:"range start,omitempty"`
 	RangeEnd    string `yaml:"range end,omitempty"`
-	SystemdName string `yaml:"systemd name" default:"dhcpd"`
+	SystemdName string `yaml:"systemd name,omitempty" default:"dhcpd"`
+}
+
+func (this DHCPConf) Enabled() bool {
+	return util.BoolP(this.EnabledP)
 }
diff --git a/internal/pkg/config/mounts.go b/internal/pkg/config/mounts.go
index 305fbad4..f228a4e5 100644
--- a/internal/pkg/config/mounts.go
+++ b/internal/pkg/config/mounts.go
@@ -1,11 +1,23 @@
 package config
 
+import (
+	"github.com/warewulf/warewulf/internal/pkg/util"
+)
+
 // A MountEntry represents a bind mount that is applied to a container
 // during exec and shell.
 type MountEntry struct {
-	Source   string `yaml:"source"`
-	Dest     string `yaml:"dest,omitempty"`
-	ReadOnly bool   `yaml:"readonly,omitempty"`
-	Options  string `yaml:"options,omitempty"` // ignored at the moment
-	Copy     bool   `yaml:"copy,omitempty"`    // temporarily copy the file into the container
+	Source    string `yaml:"source"`
+	Dest      string `yaml:"dest,omitempty"`
+	ReadOnlyP *bool  `yaml:"readonly,omitempty"`
+	Options   string `yaml:"options,omitempty"` // ignored at the moment
+	CopyP     *bool  `yaml:"copy,omitempty"`    // temporarily copy the file into the container
+}
+
+func (this MountEntry) ReadOnly() bool {
+	return util.BoolP(this.ReadOnlyP)
+}
+
+func (this MountEntry) Copy() bool {
+	return util.BoolP(this.CopyP)
 }
diff --git a/internal/pkg/config/nfs.go b/internal/pkg/config/nfs.go
index c7ad986e..ca6fc8b3 100644
--- a/internal/pkg/config/nfs.go
+++ b/internal/pkg/config/nfs.go
@@ -2,23 +2,33 @@ package config
 
 import (
 	"github.com/creasty/defaults"
+
+	"github.com/warewulf/warewulf/internal/pkg/util"
 )
 
 // NFSConf represents the NFS configuration that will be used by
 // Warewulf to generate exports on the server and mounts on compute
 // nodes.
 type NFSConf struct {
-	Enabled         bool             `yaml:"enabled" default:"true"`
-	ExportsExtended []*NFSExportConf `yaml:"export paths" default:"[]"`
-	SystemdName     string           `yaml:"systemd name" default:"nfsd"`
+	EnabledP        *bool            `yaml:"enabled,omitempty" default:"true"`
+	ExportsExtended []*NFSExportConf `yaml:"export paths,omitempty" default:"[]"`
+	SystemdName     string           `yaml:"systemd name,omitempty" default:"nfsd"`
+}
+
+func (this NFSConf) Enabled() bool {
+	return util.BoolP(this.EnabledP)
 }
 
 // An NFSExportConf reprents a single NFS export / mount.
 type NFSExportConf struct {
 	Path          string `yaml:"path" default:"/dev/null"`
-	ExportOptions string `default:"rw,sync,no_subtree_check" yaml:"export options"`
-	MountOptions  string `default:"defaults" yaml:"mount options"`
-	Mount         bool   `default:"true" yaml:"mount"`
+	ExportOptions string `yaml:"export options,omitempty" default:"rw,sync,no_subtree_check"`
+	MountOptions  string `yaml:"mount options,omitempty" default:"defaults"`
+	MountP        *bool  `yaml:"mount,omitempty" default:"true"`
+}
+
+func (this NFSExportConf) Mount() bool {
+	return util.BoolP(this.MountP)
 }
 
 // Implements the Unmarshal interface for NFSConf to set default
diff --git a/internal/pkg/config/root.go b/internal/pkg/config/root.go
index 94fae599..8655b901 100644
--- a/internal/pkg/config/root.go
+++ b/internal/pkg/config/root.go
@@ -7,6 +7,7 @@
 package config
 
 import (
+	"bytes"
 	"fmt"
 	"net"
 	"net/netip"
@@ -20,36 +21,35 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
-var cachedConf RootConf
+var cachedConf WarewulfYaml
 
-// RootConf is the main Warewulf configuration structure. It stores
+// WarewulfYaml is the main Warewulf configuration structure. It stores
 // some information about the Warewulf server locally, and has
 // [WarewulfConf], [DHCPConf], [TFTPConf], and [NFSConf] sub-sections.
-type RootConf struct {
-	WWInternal      int           `yaml:"WW_INTERNAL"`
+type WarewulfYaml struct {
 	Comment         string        `yaml:"comment,omitempty"`
-	Ipaddr          string        `yaml:"ipaddr"`
+	Ipaddr          string        `yaml:"ipaddr,omitempty"`
 	Ipaddr6         string        `yaml:"ipaddr6,omitempty"`
-	Netmask         string        `yaml:"netmask"`
+	Netmask         string        `yaml:"netmask,omitempty"`
 	Network         string        `yaml:"network,omitempty"`
 	Ipv6net         string        `yaml:"ipv6net,omitempty"`
 	Fqdn            string        `yaml:"fqdn,omitempty"`
-	Warewulf        *WarewulfConf `yaml:"warewulf"`
-	DHCP            *DHCPConf     `yaml:"dhcp"`
-	TFTP            *TFTPConf     `yaml:"tftp"`
-	NFS             *NFSConf      `yaml:"nfs"`
+	Warewulf        *WarewulfConf `yaml:"warewulf,omitempty"`
+	DHCP            *DHCPConf     `yaml:"dhcp,omitempty"`
+	TFTP            *TFTPConf     `yaml:"tftp,omitempty"`
+	NFS             *NFSConf      `yaml:"nfs,omitempty"`
 	SSH             *SSHConf      `yaml:"ssh,omitempty"`
-	MountsContainer []*MountEntry `yaml:"container mounts" default:"[{\"source\": \"/etc/resolv.conf\", \"dest\": \"/etc/resolv.conf\"}]"`
-	Paths           *BuildConfig  `yaml:"paths"`
+	MountsContainer []*MountEntry `yaml:"container mounts,omitempty" default:"[{\"source\": \"/etc/resolv.conf\", \"dest\": \"/etc/resolv.conf\"}]"`
+	Paths           *BuildConfig  `yaml:"paths,omitempty"`
 	WWClient        *WWClientConf `yaml:"wwclient,omitempty"`
 
 	warewulfconf string
 }
 
-// New caches and returns a new [RootConf] initialized with empty
+// New caches and returns a new [WarewulfYaml] initialized with empty
 // values, clearing replacing any previously cached value.
-func New() *RootConf {
-	cachedConf = RootConf{}
+func New() *WarewulfYaml {
+	cachedConf = WarewulfYaml{}
 	cachedConf.warewulfconf = ""
 	cachedConf.Warewulf = new(WarewulfConf)
 	cachedConf.DHCP = new(DHCPConf)
@@ -63,9 +63,9 @@ func New() *RootConf {
 	return &cachedConf
 }
 
-// Get returns a previously cached [RootConf] if it exists, or returns
-// a new RootConf.
-func Get() *RootConf {
+// Get returns a previously cached [WarewulfYaml] if it exists, or returns
+// a new WarewulfYaml.
+func Get() *WarewulfYaml {
 	// NOTE: This function can be called before any log level is set
 	//       so using wwlog.Verbose or wwlog.Debug won't work
 	if reflect.ValueOf(cachedConf).IsZero() {
@@ -74,9 +74,9 @@ func Get() *RootConf {
 	return &cachedConf
 }
 
-// Read populates [RootConf] with the values from a configuration
+// Read populates [WarewulfYaml] with the values from a configuration
 // file.
-func (conf *RootConf) Read(confFileName string) error {
+func (conf *WarewulfYaml) Read(confFileName string) error {
 	wwlog.Debug("Reading warewulf.conf from: %s", confFileName)
 	conf.warewulfconf = confFileName
 	if data, err := os.ReadFile(confFileName); err != nil {
@@ -88,8 +88,8 @@ func (conf *RootConf) Read(confFileName string) error {
 	}
 }
 
-// Parse populates [RootConf] with the values from a yaml document.
-func (conf *RootConf) Parse(data []byte) error {
+// Parse populates [WarewulfYaml] with the values from a yaml document.
+func (conf *WarewulfYaml) Parse(data []byte) error {
 	// ipxe binaries are merged not overwritten, store defaults separate
 	defIpxe := make(map[string]string)
 	for k, v := range conf.TFTP.IpxeBinaries {
@@ -114,13 +114,12 @@ func (conf *RootConf) Parse(data []byte) error {
 			conf.Netmask = fmt.Sprintf("%d.%d.%d.%d", mask[0], mask[1], mask[2], mask[3])
 		}
 	}
-
 	return nil
 }
 
-// SetDynamicDefaults populates [RootConf] with plausible defaults for
+// SetDynamicDefaults populates [WarewulfYaml] with plausible defaults for
 // the runtime environment.
-func (conf *RootConf) SetDynamicDefaults() (err error) {
+func (conf *WarewulfYaml) SetDynamicDefaults() (err error) {
 	if conf.Ipaddr == "" || conf.Netmask == "" || conf.Network == "" {
 		var mask net.IPMask
 		var network *net.IPNet
@@ -198,12 +197,40 @@ func (conf *RootConf) SetDynamicDefaults() (err error) {
 	return
 }
 
-// InitializedFromFile returns true if [RootConf] memory was read from
+// InitializedFromFile returns true if [WarewulfYaml] memory was read from
 // a file, or false otherwise.
-func (conf *RootConf) InitializedFromFile() bool {
+func (conf *WarewulfYaml) InitializedFromFile() bool {
 	return conf.warewulfconf != ""
 }
 
-func (conf *RootConf) GetWarewulfConf() string {
+func (conf *WarewulfYaml) GetWarewulfConf() string {
 	return conf.warewulfconf
 }
+
+func (config *WarewulfYaml) Dump() ([]byte, error) {
+	var buf bytes.Buffer
+	yamlEncoder := yaml.NewEncoder(&buf)
+	yamlEncoder.SetIndent(2)
+	err := yamlEncoder.Encode(config)
+	return buf.Bytes(), err
+}
+
+func (config *WarewulfYaml) PersistToFile(configFile string) error {
+	out, dumpErr := config.Dump()
+	if dumpErr != nil {
+		wwlog.Error("%s", dumpErr)
+		return dumpErr
+	}
+	file, err := os.OpenFile(configFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
+	if err != nil {
+		wwlog.Error("%s", err)
+		return err
+	}
+	defer file.Close()
+	_, err = file.WriteString(string(out))
+	if err != nil {
+		return err
+	}
+	wwlog.Debug("persisted: %s", configFile)
+	return nil
+}
diff --git a/internal/pkg/config/root_test.go b/internal/pkg/config/root_test.go
index 38104ffd..9b466b29 100644
--- a/internal/pkg/config/root_test.go
+++ b/internal/pkg/config/root_test.go
@@ -7,23 +7,23 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestDefaultRootConf(t *testing.T) {
+func TestDefaultWarewulfYaml(t *testing.T) {
 	conf := New()
 
 	assert.Equal(t, 9873, conf.Warewulf.Port)
-	assert.True(t, conf.Warewulf.Secure)
+	assert.True(t, conf.Warewulf.Secure())
 	assert.Equal(t, 60, conf.Warewulf.UpdateInterval)
-	assert.True(t, conf.Warewulf.AutobuildOverlays)
-	assert.True(t, conf.Warewulf.EnableHostOverlay)
-	assert.False(t, conf.Warewulf.Syslog)
+	assert.True(t, conf.Warewulf.AutobuildOverlays())
+	assert.True(t, conf.Warewulf.EnableHostOverlay())
+	assert.False(t, conf.Warewulf.Syslog())
 
-	assert.True(t, conf.DHCP.Enabled)
+	assert.True(t, conf.DHCP.Enabled())
 	assert.Equal(t, "default", conf.DHCP.Template)
 	assert.Empty(t, conf.DHCP.RangeStart)
 	assert.Empty(t, conf.DHCP.RangeEnd)
 	assert.Equal(t, "dhcpd", conf.DHCP.SystemdName)
 
-	assert.True(t, conf.TFTP.Enabled)
+	assert.True(t, conf.TFTP.Enabled())
 	assert.NotEmpty(t, conf.TFTP.TftpRoot)
 	assert.Equal(t, "tftp", conf.TFTP.SystemdName)
 	assert.NotEmpty(t, conf.TFTP.IpxeBinaries["00:00"])
@@ -31,13 +31,13 @@ func TestDefaultRootConf(t *testing.T) {
 	assert.NotEmpty(t, conf.TFTP.IpxeBinaries["00:09"])
 	assert.NotEmpty(t, conf.TFTP.IpxeBinaries["00:0B"])
 
-	assert.True(t, conf.NFS.Enabled)
+	assert.True(t, conf.NFS.Enabled())
 	assert.Empty(t, conf.NFS.ExportsExtended)
 	assert.Equal(t, "nfsd", conf.NFS.SystemdName)
 
 	assert.Equal(t, "/etc/resolv.conf", conf.MountsContainer[0].Source)
 	assert.Equal(t, "/etc/resolv.conf", conf.MountsContainer[0].Dest)
-	assert.False(t, conf.MountsContainer[0].ReadOnly)
+	assert.False(t, conf.MountsContainer[0].ReadOnly())
 	assert.Empty(t, conf.MountsContainer[0].Options)
 
 	assert.NotEmpty(t, conf.Paths.Bindir)
@@ -54,7 +54,7 @@ func TestDefaultRootConf(t *testing.T) {
 }
 
 func TestInitializedFromFile(t *testing.T) {
-	example_warewulf_conf := "WW_INTERNAL: 45"
+	example_warewulf_conf := ""
 	tempWarewulfConf, warewulfConfErr := os.CreateTemp("", "warewulf.conf-")
 	assert.NoError(t, warewulfConfErr)
 	defer os.Remove(tempWarewulfConf.Name())
@@ -69,8 +69,8 @@ func TestInitializedFromFile(t *testing.T) {
 	assert.Equal(t, conf.GetWarewulfConf(), tempWarewulfConf.Name())
 }
 
-func TestExampleRootConf(t *testing.T) {
-	example_warewulf_conf := `WW_INTERNAL: 45
+func TestExampleWarewulfYaml(t *testing.T) {
+	example_warewulf_conf := `
 ipaddr: 192.168.200.1
 netmask: 255.255.255.0
 network: 192.168.200.0
@@ -121,34 +121,34 @@ container mounts:
 	assert.Equal(t, "192.168.200.0", conf.Network)
 
 	assert.Equal(t, 9873, conf.Warewulf.Port)
-	assert.False(t, conf.Warewulf.Secure)
+	assert.False(t, conf.Warewulf.Secure())
 	assert.Equal(t, 60, conf.Warewulf.UpdateInterval)
-	assert.True(t, conf.Warewulf.AutobuildOverlays)
-	assert.True(t, conf.Warewulf.EnableHostOverlay)
-	assert.False(t, conf.Warewulf.Syslog)
+	assert.True(t, conf.Warewulf.AutobuildOverlays())
+	assert.True(t, conf.Warewulf.EnableHostOverlay())
+	assert.False(t, conf.Warewulf.Syslog())
 
-	assert.True(t, conf.DHCP.Enabled)
+	assert.True(t, conf.DHCP.Enabled())
 	assert.Equal(t, "192.168.200.50", conf.DHCP.RangeStart)
 	assert.Equal(t, "192.168.200.99", conf.DHCP.RangeEnd)
 	assert.Equal(t, "dhcpd", conf.DHCP.SystemdName)
 
-	assert.True(t, conf.TFTP.Enabled)
+	assert.True(t, conf.TFTP.Enabled())
 	assert.Equal(t, "tftp", conf.TFTP.SystemdName)
 
-	assert.True(t, conf.NFS.Enabled)
+	assert.True(t, conf.NFS.Enabled())
 	assert.Equal(t, "/home", conf.NFS.ExportsExtended[0].Path)
 	assert.Equal(t, "rw,sync", conf.NFS.ExportsExtended[0].ExportOptions)
 	assert.Equal(t, "defaults", conf.NFS.ExportsExtended[0].MountOptions)
-	assert.True(t, conf.NFS.ExportsExtended[0].Mount)
+	assert.True(t, conf.NFS.ExportsExtended[0].Mount())
 	assert.Equal(t, "/opt", conf.NFS.ExportsExtended[1].Path)
 	assert.Equal(t, "ro,sync,no_root_squash", conf.NFS.ExportsExtended[1].ExportOptions)
 	assert.Equal(t, "defaults", conf.NFS.ExportsExtended[1].MountOptions)
-	assert.False(t, conf.NFS.ExportsExtended[1].Mount)
+	assert.False(t, conf.NFS.ExportsExtended[1].Mount())
 	assert.Equal(t, "nfs-server", conf.NFS.SystemdName)
 
 	assert.Equal(t, "/etc/resolv.conf", conf.MountsContainer[0].Source)
 	assert.Equal(t, "/etc/resolv.conf", conf.MountsContainer[0].Dest)
-	assert.True(t, conf.MountsContainer[0].ReadOnly)
+	assert.True(t, conf.MountsContainer[0].ReadOnly())
 }
 
 func TestCache(t *testing.T) {
diff --git a/internal/pkg/config/ssh.go b/internal/pkg/config/ssh.go
index a9abe4dc..5e08aac7 100644
--- a/internal/pkg/config/ssh.go
+++ b/internal/pkg/config/ssh.go
@@ -1,5 +1,5 @@
 package config
 
 type SSHConf struct {
-	KeyTypes []string `yaml:"key types" default:"[\"rsa\",\"dsa\",\"ecdsa\",\"ed25519\"]"`
+	KeyTypes []string `yaml:"key types,omitempty" default:"[\"rsa\",\"dsa\",\"ecdsa\",\"ed25519\"]"`
 }
diff --git a/internal/pkg/config/wwclient.go b/internal/pkg/config/wwclient.go
index 13993be6..52d92d04 100644
--- a/internal/pkg/config/wwclient.go
+++ b/internal/pkg/config/wwclient.go
@@ -1,5 +1,5 @@
 package config
 
 type WWClientConf struct {
-	Port uint16 `yaml:"port" default:"0"`
+	Port uint16 `yaml:"port,omitempty" default:"0"`
 }
diff --git a/internal/pkg/configure/dhcp.go b/internal/pkg/configure/dhcp.go
index 85fd2c03..95f6c816 100644
--- a/internal/pkg/configure/dhcp.go
+++ b/internal/pkg/configure/dhcp.go
@@ -17,7 +17,7 @@ func DHCP() (err error) {
 
 	controller := warewulfconf.Get()
 
-	if !controller.DHCP.Enabled {
+	if !controller.DHCP.Enabled() {
 		wwlog.Warn("This system is not configured as a Warewulf DHCP controller")
 		return
 	}
@@ -29,7 +29,7 @@ func DHCP() (err error) {
 	if controller.DHCP.RangeEnd == "" {
 		return fmt.Errorf("configuration is not defined: `dhcpd range end`")
 	}
-	if controller.Warewulf.EnableHostOverlay {
+	if controller.Warewulf.EnableHostOverlay() {
 		err = overlay.BuildHostOverlay()
 		if err != nil {
 			wwlog.Warn("host overlay could not be built: %s", err)
diff --git a/internal/pkg/configure/nfs.go b/internal/pkg/configure/nfs.go
index d68916d3..62a9dd1a 100644
--- a/internal/pkg/configure/nfs.go
+++ b/internal/pkg/configure/nfs.go
@@ -17,8 +17,8 @@ func NFS() error {
 
 	controller := warewulfconf.Get()
 
-	if controller.NFS.Enabled {
-		if controller.Warewulf.EnableHostOverlay {
+	if controller.NFS.Enabled() {
+		if controller.Warewulf.EnableHostOverlay() {
 			err := overlay.BuildHostOverlay()
 			if err != nil {
 				wwlog.Warn("host overlay could not be built: %s", err)
diff --git a/internal/pkg/configure/tftp.go b/internal/pkg/configure/tftp.go
index c693cb5d..41c8d556 100644
--- a/internal/pkg/configure/tftp.go
+++ b/internal/pkg/configure/tftp.go
@@ -21,7 +21,7 @@ func TFTP() (err error) {
 		return
 	}
 
-	if controller.Warewulf.GrubBoot {
+	if controller.Warewulf.GrubBoot() {
 		err := warewulfd.CopyShimGrub()
 		if err != nil {
 			wwlog.Warn("error when copying shim/grub binaries: %s", err)
@@ -43,7 +43,7 @@ func TFTP() (err error) {
 			}
 		}
 	}
-	if !controller.TFTP.Enabled {
+	if !controller.TFTP.Enabled() {
 		wwlog.Warn("Warewulf does not auto start TFTP services due to disable by warewulf.conf")
 		return nil
 	}
diff --git a/internal/pkg/container/mountpoints.go b/internal/pkg/container/mountpoints.go
index 961513fb..07c7b57e 100644
--- a/internal/pkg/container/mountpoints.go
+++ b/internal/pkg/container/mountpoints.go
@@ -30,10 +30,10 @@ func InitMountPnts(binds []string) (mounts []*warewulfconf.MountEntry) {
 			}
 		}
 		mntPnt := warewulfconf.MountEntry{
-			Source:   bind[0],
-			Dest:     dest,
-			ReadOnly: readonly,
-			Copy:     copy_,
+			Source:    bind[0],
+			Dest:      dest,
+			ReadOnlyP: &readonly,
+			CopyP:     &copy_,
 		}
 		mounts = append(mounts, &mntPnt)
 	}
diff --git a/internal/pkg/node/checkconf.go b/internal/pkg/node/checkconf.go
index 623f078f..e80ecd01 100644
--- a/internal/pkg/node/checkconf.go
+++ b/internal/pkg/node/checkconf.go
@@ -14,13 +14,13 @@ import (
 /*
 Checks if for NodeConf all values can be parsed according to their type.
 */
-func (nodeConf *NodeConf) Check() (err error) {
+func (nodeConf *Node) Check() (err error) {
 	nodeInfoType := reflect.TypeOf(nodeConf)
 	nodeInfoVal := reflect.ValueOf(nodeConf)
 	return check(nodeInfoType, nodeInfoVal)
 }
 
-func (profileConf *ProfileConf) Check() (err error) {
+func (profileConf *Profile) Check() (err error) {
 	profileInfoType := reflect.TypeOf(profileConf)
 	profileInfoVal := reflect.ValueOf(profileConf)
 	return check(profileInfoType, profileInfoVal)
@@ -49,8 +49,8 @@ func check(infoType reflect.Type, infoVal reflect.Value) (err error) {
 					}
 				}
 			}
-		} else if infoType.Elem().Field(i).Type == reflect.TypeOf(map[string]*NetDevs(nil)) {
-			netMap := infoVal.Elem().Field(i).Interface().(map[string]*NetDevs)
+		} else if infoType.Elem().Field(i).Type == reflect.TypeOf(map[string]*NetDev(nil)) {
+			netMap := infoVal.Elem().Field(i).Interface().(map[string]*NetDev)
 			for _, val := range netMap {
 				netType := reflect.TypeOf(val)
 				netVal := reflect.ValueOf(val)
diff --git a/internal/pkg/node/constructors.go b/internal/pkg/node/constructors.go
index 88fec481..7e00ed7a 100644
--- a/internal/pkg/node/constructors.go
+++ b/internal/pkg/node/constructors.go
@@ -18,18 +18,21 @@ var (
 	ConfigFile string
 )
 
-/*
-Creates a new nodeDb object from the on-disk configuration
-*/
-func New() (NodeYaml, error) {
+func init() {
 	conf := warewulfconf.Get()
 	if ConfigFile == "" {
 		ConfigFile = path.Join(conf.Paths.Sysconfdir, "warewulf/nodes.conf")
 	}
+}
+
+/*
+Creates a new nodeDb object from the on-disk configuration
+*/
+func New() (NodesYaml, error) {
 	wwlog.Verbose("Opening node configuration file: %s", ConfigFile)
 	data, err := os.ReadFile(ConfigFile)
 	if err != nil {
-		return NodeYaml{}, err
+		return NodesYaml{}, err
 	}
 	return Parse(data)
 }
@@ -38,18 +41,18 @@ func New() (NodeYaml, error) {
 // document. Passes any errors return from yaml.Unmarshal. Returns an
 // error if any parsed value is not of a valid type for the given
 // parameter.
-func Parse(data []byte) (nodeList NodeYaml, err error) {
+func Parse(data []byte) (nodeList NodesYaml, err error) {
 	wwlog.Debug("Unmarshaling the node configuration")
 	err = yaml.Unmarshal(data, &nodeList)
 	if err != nil {
 		return nodeList, err
 	}
 	wwlog.Debug("Checking nodes for types")
-	if nodeList.nodes == nil {
-		nodeList.nodes = map[string]*NodeConf{}
+	if nodeList.Nodes == nil {
+		nodeList.Nodes = map[string]*Node{}
 	}
-	if nodeList.nodeProfiles == nil {
-		nodeList.nodeProfiles = map[string]*ProfileConf{}
+	if nodeList.NodeProfiles == nil {
+		nodeList.NodeProfiles = map[string]*Profile{}
 	}
 	wwlog.Debug("returning node object")
 	return nodeList, nil
@@ -58,8 +61,8 @@ func Parse(data []byte) (nodeList NodeYaml, err error) {
 /*
 Get a node with its merged in nodes
 */
-func (config *NodeYaml) GetNode(id string) (node NodeConf, err error) {
-	if _, ok := config.nodes[id]; !ok {
+func (config *NodesYaml) GetNode(id string) (node Node, err error) {
+	if _, ok := config.Nodes[id]; !ok {
 		return node, ErrNotFound
 	}
 	node = EmptyNode()
@@ -68,7 +71,7 @@ func (config *NodeYaml) GetNode(id string) (node NodeConf, err error) {
 	var buf bytes.Buffer
 	enc := gob.NewEncoder(&buf)
 	dec := gob.NewDecoder(&buf)
-	err = enc.Encode(config.nodes[id])
+	err = enc.Encode(config.Nodes[id])
 	if err != nil {
 		return node, err
 	}
@@ -76,13 +79,13 @@ func (config *NodeYaml) GetNode(id string) (node NodeConf, err error) {
 	if err != nil {
 		return node, err
 	}
-	for _, p := range cleanList(config.nodes[id].Profiles) {
+	for _, p := range cleanList(config.Nodes[id].Profiles) {
 		includedProfile, err := config.GetProfile(p)
 		if err != nil {
 			wwlog.Warn("profile not found: %s", p)
 			continue
 		}
-		err = mergo.Merge(&node.ProfileConf, includedProfile, mergo.WithAppendSlice)
+		err = mergo.Merge(&node.Profile, includedProfile, mergo.WithAppendSlice)
 		if err != nil {
 			return node, err
 		}
@@ -112,9 +115,9 @@ func (config *NodeYaml) GetNode(id string) (node NodeConf, err error) {
 Return the node with the id string without the merged in nodes, return ErrNotFound
 otherwise
 */
-func (config *NodeYaml) GetNodeOnly(id string) (node NodeConf, err error) {
+func (config *NodesYaml) GetNodeOnly(id string) (node Node, err error) {
 	node = EmptyNode()
-	if found, ok := config.nodes[id]; ok {
+	if found, ok := config.Nodes[id]; ok {
 		return *found, nil
 	}
 	return node, ErrNotFound
@@ -124,9 +127,9 @@ func (config *NodeYaml) GetNodeOnly(id string) (node NodeConf, err error) {
 Return pointer to the  node with the id string without the merged in nodes, return ErrMotFound
 otherwise
 */
-func (config *NodeYaml) GetNodeOnlyPtr(id string) (*NodeConf, error) {
+func (config *NodesYaml) GetNodeOnlyPtr(id string) (*Node, error) {
 	node := EmptyNode()
-	if found, ok := config.nodes[id]; ok {
+	if found, ok := config.Nodes[id]; ok {
 		return found, nil
 	}
 	return &node, ErrNotFound
@@ -135,8 +138,8 @@ func (config *NodeYaml) GetNodeOnlyPtr(id string) (*NodeConf, error) {
 /*
 Get the profile with id, return ErrNotFound otherwise
 */
-func (config *NodeYaml) GetProfile(id string) (profile ProfileConf, err error) {
-	if found, ok := config.nodeProfiles[id]; ok {
+func (config *NodesYaml) GetProfile(id string) (profile Profile, err error) {
+	if found, ok := config.NodeProfiles[id]; ok {
 		found.id = id
 		return *found, nil
 	}
@@ -146,8 +149,8 @@ func (config *NodeYaml) GetProfile(id string) (profile ProfileConf, err error) {
 /*
 Get the profile with id, return ErrNotFound otherwise
 */
-func (config *NodeYaml) GetProfilePtr(id string) (profile *ProfileConf, err error) {
-	if found, ok := config.nodeProfiles[id]; ok {
+func (config *NodesYaml) GetProfilePtr(id string) (profile *Profile, err error) {
+	if found, ok := config.NodeProfiles[id]; ok {
 		found.id = id
 		return found, nil
 	}
@@ -158,9 +161,9 @@ func (config *NodeYaml) GetProfilePtr(id string) (profile *ProfileConf, err erro
 Get the nodes from the loaded configuration. This function also merges
 the nodes with the given nodes.
 */
-func (config *NodeYaml) FindAllNodes(nodes ...string) (nodeList []NodeConf, err error) {
+func (config *NodesYaml) FindAllNodes(nodes ...string) (nodeList []Node, err error) {
 	if len(nodes) == 0 {
-		for n := range config.nodes {
+		for n := range config.Nodes {
 			nodes = append(nodes, n)
 		}
 	}
@@ -188,9 +191,9 @@ func (config *NodeYaml) FindAllNodes(nodes ...string) (nodeList []NodeConf, err
 /*
 Return all nodes as ProfileConf
 */
-func (config *NodeYaml) FindAllProfiles(nodes ...string) (profileList []ProfileConf, err error) {
+func (config *NodesYaml) FindAllProfiles(nodes ...string) (profileList []Profile, err error) {
 	if len(nodes) == 0 {
-		for n := range config.nodeProfiles {
+		for n := range config.NodeProfiles {
 			nodes = append(nodes, n)
 		}
 	}
@@ -219,9 +222,9 @@ func (config *NodeYaml) FindAllProfiles(nodes ...string) (profileList []ProfileC
 /*
 Return the names of all available nodes
 */
-func (config *NodeYaml) ListAllNodes() []string {
-	nodeList := make([]string, len(config.nodes))
-	for name := range config.nodes {
+func (config *NodesYaml) ListAllNodes() []string {
+	nodeList := make([]string, len(config.Nodes))
+	for name := range config.Nodes {
 		nodeList = append(nodeList, name)
 	}
 	return nodeList
@@ -230,9 +233,9 @@ func (config *NodeYaml) ListAllNodes() []string {
 /*
 Return the names of all available nodes
 */
-func (config *NodeYaml) ListAllProfiles() []string {
+func (config *NodesYaml) ListAllProfiles() []string {
 	var nodeList []string
-	for name := range config.nodeProfiles {
+	for name := range config.NodeProfiles {
 		nodeList = append(nodeList, name)
 	}
 	return nodeList
@@ -246,7 +249,7 @@ without a hardware address is returned.
 
 If no unconfigured node is found, an error is returned.
 */
-func (config *NodeYaml) FindDiscoverableNode() (NodeConf, string, error) {
+func (config *NodesYaml) FindDiscoverableNode() (Node, string, error) {
 
 	nodes, _ := config.FindAllNodes()
 
diff --git a/internal/pkg/node/constuctors_test.go b/internal/pkg/node/constructors_test.go
similarity index 97%
rename from internal/pkg/node/constuctors_test.go
rename to internal/pkg/node/constructors_test.go
index ec0171cf..cec97419 100644
--- a/internal/pkg/node/constuctors_test.go
+++ b/internal/pkg/node/constructors_test.go
@@ -8,7 +8,7 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
-func newConstructorPrimaryNetworkTest(t *testing.T) NodeYaml {
+func newConstructorPrimaryNetworkTest(t *testing.T) NodesYaml {
 	var data = `
 nodeprofiles:
   default:
@@ -53,7 +53,7 @@ nodes:
       override:
         device: ib1
   `
-	var ret NodeYaml
+	var ret NodesYaml
 	err := yaml.Unmarshal([]byte(data), &ret)
 	assert.NoError(t, err)
 	return ret
@@ -138,7 +138,7 @@ func Test_FindDiscoverableNode(t *testing.T) {
 		t.Run(tt.description, func(t *testing.T) {
 			config := newConstructorPrimaryNetworkTest(t)
 			for _, node := range tt.discoverable_nodes {
-				config.nodes[node].Discoverable = "true"
+				config.Nodes[node].Discoverable = "true"
 			}
 			discovered_node, discovered_interface, err := config.FindDiscoverableNode()
 			if !tt.succeed {
@@ -193,13 +193,13 @@ nodes:
       - profile2
 `
 	assert := assert.New(t)
-	var ymlSrc NodeYaml
+	var ymlSrc NodesYaml
 	err := yaml.Unmarshal([]byte(nodesconf), &ymlSrc)
 	assert.NoError(err)
 	wwlog.SetLogLevel(wwlog.DEBUG)
 	nodes, err := ymlSrc.FindAllNodes()
 	assert.NoError(err)
-	nodemap := make(map[string]*NodeConf)
+	nodemap := make(map[string]*Node)
 	for i := range nodes {
 		nodemap[nodes[i].Id()] = &nodes[i]
 	}
diff --git a/internal/pkg/node/datastructure.go b/internal/pkg/node/datastructure.go
index bf44236b..cc48b5d3 100644
--- a/internal/pkg/node/datastructure.go
+++ b/internal/pkg/node/datastructure.go
@@ -3,9 +3,7 @@ package node
 import (
 	"net"
 
-	"github.com/warewulf/warewulf/internal/pkg/wwlog"
 	"github.com/warewulf/warewulf/internal/pkg/wwtype"
-	"gopkg.in/yaml.v3"
 )
 
 const undef string = "UNDEF"
@@ -16,29 +14,28 @@ const undef string = "UNDEF"
 /*
 Structure of which goes to disk
 */
-type NodeYaml struct {
-	WWInternal   int `yaml:"WW_INTERNAL,omitempty" json:"WW_INTERNAL,omitempty"`
-	nodeProfiles map[string]*ProfileConf
-	nodes        map[string]*NodeConf
+type NodesYaml struct {
+	NodeProfiles map[string]*Profile
+	Nodes        map[string]*Node
 }
 
 /*
-NodeConf is the datastructure describing a node and a profile which in disk format.
+Node is the datastructure describing a node and a profile which in disk format.
 */
-type NodeConf struct {
+type Node struct {
 	id    string
 	valid bool // Is set true, if called by the constructor
 	// exported values
 	Discoverable wwtype.WWbool     `yaml:"discoverable,omitempty" lopt:"discoverable" sopt:"e" comment:"Make discoverable in given network (true/false)"`
 	AssetKey     string            `yaml:"asset key,omitempty" lopt:"asset" comment:"Set the node's Asset tag (key)"`
 	Profiles     []string          `yaml:"profiles,omitempty" lopt:"profile" sopt:"P" comment:"Set the node's profile members (comma separated)"`
-	ProfileConf  `yaml:"-,inline"` // include all values set in the profile, but inline them in yaml output if these are part of NodeConf
+	Profile      `yaml:"-,inline"` // include all values set in the profile, but inline them in yaml output if these are part of Node
 }
 
 /*
 Holds the data which can be set for profiles and nodes.
 */
-type ProfileConf struct {
+type Profile struct {
 	id string
 	// exported values
 	Comment        string                 `yaml:"comment,omitempty" lopt:"comment" comment:"Set arbitrary string comment"`
@@ -51,7 +48,7 @@ type ProfileConf struct {
 	Ipmi           *IpmiConf              `yaml:"ipmi,omitempty"`
 	Init           string                 `yaml:"init,omitempty" lopt:"init" sopt:"i" comment:"Define the init process to boot the container"`
 	Root           string                 `yaml:"root,omitempty" lopt:"root" comment:"Define the rootfs" `
-	NetDevs        map[string]*NetDevs    `yaml:"network devices,omitempty"`
+	NetDevs        map[string]*NetDev     `yaml:"network devices,omitempty"`
 	Tags           map[string]string      `yaml:"tags,omitempty"`
 	PrimaryNetDev  string                 `yaml:"primary network,omitempty" lopt:"primarynet" sopt:"p" comment:"Set the primary network interface"`
 	Disks          map[string]*Disk       `yaml:"disks,omitempty"`
@@ -78,9 +75,9 @@ type KernelConf struct {
 	Args     string `yaml:"args,omitempty" lopt:"kernelargs" sopt:"A" comment:"Set Kernel argument" json:"args,omitempty"`
 }
 
-type NetDevs struct {
+type NetDev struct {
 	Type    string            `yaml:"type,omitempty" lopt:"type" sopt:"T" comment:"Set device type of given network"`
-	OnBoot  *bool             `yaml:"onboot,omitempty" lopt:"onboot" comment:"Enable/disable network device (true/false)"`
+	OnBoot  wwtype.WWbool     `yaml:"onboot,omitempty" lopt:"onboot" comment:"Enable/disable network device (true/false)"`
 	Device  string            `yaml:"device,omitempty" lopt:"netdev" sopt:"N" comment:"Set the device for given network"`
 	Hwaddr  string            `yaml:"hwaddr,omitempty" lopt:"hwaddr" sopt:"H" comment:"Set the device's HW address for given network" type:"MAC"`
 	Ipaddr  net.IP            `yaml:"ipaddr,omitempty" comment:"IPv4 address in given network" sopt:"I" lopt:"ipaddr" type:"IP"`
@@ -107,7 +104,7 @@ Partitions map
 */
 type Partition struct {
 	Number             string `yaml:"number,omitempty" lopt:"partnumber" comment:"set the partition number, if not set next free slot is used" type:"uint"`
-	SizeMiB            string `yaml:"size_mib,omitempty" lopt:"partsize " comment:"set the size of the partition, if not set maximal possible size is used"  type:"uint"`
+	SizeMiB            string `yaml:"size_mib,omitempty" lopt:"partsize" comment:"set the size of the partition, if not set maximal possible size is used"  type:"uint"`
 	StartMiB           string `yaml:"start_mib,omitempty" comment:"the start of the partition" type:"uint"`
 	TypeGuid           string `yaml:"type_guid,omitempty" comment:"Linux filesystem data will be used if empty"`
 	Guid               string `yaml:"guid,omitempty" comment:"the GPT unique partition GUID"`
@@ -128,48 +125,3 @@ type FileSystem struct {
 	Options        []string `yaml:"options,omitempty" comment:"any additional options to be passed to the format-specific mkfs utility"`
 	MountOptions   string   `yaml:"mount_options,omitempty" comment:"any special options to be passed to the mount command"`
 }
-
-/*
-interface so that nodes and profiles which aren't exported will
-be marshaled
-*/
-type ExportedYml struct {
-	WWInternal   int                     `yaml:"WW_INTERNAL"`
-	NodeProfiles map[string]*ProfileConf `yaml:"nodeprofiles"`
-	Nodes        map[string]*NodeConf    `yaml:"nodes"`
-}
-
-/*
-Marshall Exported stuff, not NodeYaml directly
-*/
-func (yml *NodeYaml) MarshalYAML() (interface{}, error) {
-	wwlog.Debug("marshall yml")
-	var exp ExportedYml
-	exp.WWInternal = yml.WWInternal
-	exp.Nodes = yml.nodes
-	exp.NodeProfiles = yml.nodeProfiles
-	node := yaml.Node{}
-	err := node.Encode(exp)
-	if err != nil {
-		return node, err
-	}
-	return node, err
-}
-
-/*
-Unmarshal to intermediate format
-*/
-func (yml *NodeYaml) UnmarshalYAML(
-	unmarshal func(interface{}) (err error),
-) (err error) {
-	wwlog.Debug("UnmarshalYAML called")
-	var exp ExportedYml
-	err = unmarshal(&exp)
-	if err != nil {
-		return
-	}
-	yml.WWInternal = exp.WWInternal
-	yml.nodes = exp.Nodes
-	yml.nodeProfiles = exp.NodeProfiles
-	return nil
-}
diff --git a/internal/pkg/node/flags.go b/internal/pkg/node/flags.go
index e87c750d..62dad5e1 100644
--- a/internal/pkg/node/flags.go
+++ b/internal/pkg/node/flags.go
@@ -31,11 +31,11 @@ type NodeConfAdd struct {
 Create cmd line flags from the NodeConf fields. Returns a []func() where every function must be called, as the command line parser returns e.g. netip.IP objects which must be parsed
 back to strings.
 */
-func (nodeConf *NodeConf) CreateFlags(baseCmd *cobra.Command) {
+func (nodeConf *Node) CreateFlags(baseCmd *cobra.Command) {
 	recursiveCreateFlags(nodeConf, baseCmd)
 }
 
-func (profileConf *ProfileConf) CreateFlags(baseCmd *cobra.Command) {
+func (profileConf *Profile) CreateFlags(baseCmd *cobra.Command) {
 	recursiveCreateFlags(profileConf, baseCmd)
 }
 
diff --git a/internal/pkg/node/hash.go b/internal/pkg/node/hash.go
index 1c57dce9..757a1879 100644
--- a/internal/pkg/node/hash.go
+++ b/internal/pkg/node/hash.go
@@ -11,12 +11,12 @@ import (
 /*
 Calculate the hash of NodeYaml in an orderder fashion
 */
-func (config *NodeYaml) Hash() [32]byte {
+func (config *NodesYaml) Hash() [32]byte {
 	// flatten out profiles and nodes
-	for _, val := range config.nodeProfiles {
+	for _, val := range config.NodeProfiles {
 		val.Flatten()
 	}
-	for _, val := range config.nodes {
+	for _, val := range config.Nodes {
 		val.Flatten()
 	}
 	data, err := yaml.Marshal(config)
@@ -29,7 +29,7 @@ func (config *NodeYaml) Hash() [32]byte {
 /*
 Return the hash as string
 */
-func (config *NodeYaml) StringHash() string {
+func (config *NodesYaml) StringHash() string {
 	buffer := config.Hash()
 	return hex.EncodeToString(buffer[:])
 }
diff --git a/internal/pkg/node/hash_test.go b/internal/pkg/node/hash_test.go
index 482a7ef8..8fc66e79 100644
--- a/internal/pkg/node/hash_test.go
+++ b/internal/pkg/node/hash_test.go
@@ -10,7 +10,6 @@ import (
 
 func TestHash(t *testing.T) {
 	nodeConfYml1 := `
-WW_INTERNAL: 45
 nodeprofiles:
   default:
     comment: This profile is automatically included for each node
@@ -33,7 +32,6 @@ nodes:
         ipaddr: 10.0.10.2
 `
 	nodeConfYml2 := `
-WW_INTERNAL: 45
 nodeprofiles:
   default:
     comment: This profile is automatically included for each node
@@ -56,7 +54,6 @@ nodes:
         ipaddr: 10.0.10.1
 `
 	nodeConfYml3 := `
-WW_INTERNAL: 45
 nodeprofiles:
   default:
     comment: This profile is automatically included for each node
@@ -78,7 +75,7 @@ nodes:
       default:
         ipaddr: 10.0.10.3
 `
-	var nodeConf1, nodeConf2, nodeConf3 NodeYaml
+	var nodeConf1, nodeConf2, nodeConf3 NodesYaml
 	err := yaml.Unmarshal([]byte(nodeConfYml1), &nodeConf1)
 	assert.NoError(t, err)
 	err = yaml.Unmarshal([]byte(nodeConfYml2), &nodeConf2)
@@ -87,7 +84,7 @@ nodes:
 	assert.NoError(t, err)
 
 	t.Run("Same NodeYaml with same conf", func(t *testing.T) {
-		var testConf NodeYaml
+		var testConf NodesYaml
 		err = yaml.Unmarshal([]byte(nodeConfYml1), &testConf)
 		assert.NoError(t, err)
 		if testConf.Hash() != nodeConf1.Hash() {
diff --git a/internal/pkg/node/ignition.go b/internal/pkg/node/ignition.go
index fbffab87..c3ac4e96 100644
--- a/internal/pkg/node/ignition.go
+++ b/internal/pkg/node/ignition.go
@@ -13,7 +13,7 @@ import (
 /*
 Create a ignition struct class for ignition
 */
-func (node *NodeConf) GetStorage() (stor types_3_4.Storage, err error, rep string) {
+func (node *Node) GetStorage() (stor types_3_4.Storage, err error, rep string) {
 	var fileSystems []types_3_4.Filesystem
 	for fsdevice, fs := range node.FileSystems {
 		var mountOptions []types_3_4.MountOption
@@ -141,7 +141,7 @@ type SimpleIgnitionConfig struct {
 /*
 Get a simple config which can be marshalled to json
 */
-func (node *NodeConf) GetConfig() (conf SimpleIgnitionConfig, rep string, err error) {
+func (node *Node) GetConfig() (conf SimpleIgnitionConfig, rep string, err error) {
 	conf.Storage, err, rep = node.GetStorage()
 	conf.Ignition.Version = "3.1.0"
 	return
diff --git a/internal/pkg/node/list.go b/internal/pkg/node/list.go
index 17d9ba02..0cabf65e 100644
--- a/internal/pkg/node/list.go
+++ b/internal/pkg/node/list.go
@@ -41,10 +41,10 @@ type fieldMap map[string]*NodeFields
 /*
 Get all the info out of NodeConf. If emptyFields is set true, all fields are shown not only the ones with effective values
 */
-func (nodeYml *NodeYaml) GetFields(node NodeConf) (output []NodeFields) {
+func (nodeYml *NodesYaml) GetFields(node Node) (output []NodeFields) {
 	nodeMap := make(fieldMap)
 	for _, p := range node.Profiles {
-		if profile, ok := nodeYml.nodeProfiles[p]; ok {
+		if profile, ok := nodeYml.NodeProfiles[p]; ok {
 			nodeMap.importFields(profile, "", p)
 		}
 	}
@@ -64,7 +64,7 @@ func (nodeYml *NodeYaml) GetFields(node NodeConf) (output []NodeFields) {
 /*
 Get all the info out of ProfileConf. If emptyFields is set true, all fields are shown not only the ones with effective values
 */
-func (nodeYml *NodeYaml) GetFieldsProfile(profile ProfileConf) (output []NodeFields) {
+func (nodeYml *NodesYaml) GetFieldsProfile(profile Profile) (output []NodeFields) {
 	profileMap := make(fieldMap)
 	profileMap.importFields(&profile, "", "")
 	for _, elem := range profileMap {
diff --git a/internal/pkg/node/methods.go b/internal/pkg/node/methods.go
index ea449145..4e1ca218 100644
--- a/internal/pkg/node/methods.go
+++ b/internal/pkg/node/methods.go
@@ -10,13 +10,13 @@ import (
 	"github.com/warewulf/warewulf/internal/pkg/util"
 )
 
-type nodeList []NodeConf
+type nodeList []Node
 
 func (a nodeList) Len() int           { return len(a) }
 func (a nodeList) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 func (a nodeList) Less(i, j int) bool { return a[i].id < a[j].id }
 
-type profileList []ProfileConf
+type profileList []Profile
 
 func (a profileList) Len() int           { return len(a) }
 func (a profileList) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
@@ -32,9 +32,9 @@ func (a profileList) Less(i, j int) bool { return a[i].id < a[j].id }
 Filter a given slice of NodeConf against a given
 regular expression
 */
-func FilterNodeListByName(set []NodeConf, searchList []string) []NodeConf {
-	var ret []NodeConf
-	unique := make(map[string]NodeConf)
+func FilterNodeListByName(set []Node, searchList []string) []Node {
+	var ret []Node
+	unique := make(map[string]Node)
 
 	if len(searchList) > 0 {
 		for _, search := range searchList {
@@ -59,9 +59,9 @@ func FilterNodeListByName(set []NodeConf, searchList []string) []NodeConf {
 Filter a given slice of ProfileConf against a given
 regular expression
 */
-func FilterProfileListByName(set []ProfileConf, searchList []string) []ProfileConf {
-	var ret []ProfileConf
-	unique := make(map[string]ProfileConf)
+func FilterProfileListByName(set []Profile, searchList []string) []Profile {
+	var ret []Profile
+	unique := make(map[string]Profile)
 
 	if len(searchList) > 0 {
 		for _, search := range searchList {
@@ -85,23 +85,23 @@ func FilterProfileListByName(set []ProfileConf, searchList []string) []ProfileCo
 /*
 Creates an NodeConf with the given id. Doesn't add it to the database
 */
-func NewNode(id string) (nodeconf NodeConf) {
+func NewNode(id string) (nodeconf Node) {
 	nodeconf = EmptyNode()
 	nodeconf.id = id
 	return nodeconf
 }
 
-func NewProfile(id string) (profileconf ProfileConf) {
+func NewProfile(id string) (profileconf Profile) {
 	profileconf = EmptyProfile()
 	profileconf.id = id
 	return profileconf
 }
 
-func EmptyNode() (nodeconf NodeConf) {
+func EmptyNode() (nodeconf Node) {
 	nodeconf.Ipmi = new(IpmiConf)
 	nodeconf.Ipmi.Tags = map[string]string{}
 	nodeconf.Kernel = new(KernelConf)
-	nodeconf.NetDevs = make(map[string]*NetDevs)
+	nodeconf.NetDevs = make(map[string]*NetDev)
 	nodeconf.Tags = map[string]string{}
 	return nodeconf
 }
@@ -109,11 +109,11 @@ func EmptyNode() (nodeconf NodeConf) {
 /*
 Creates a ProfileConf but doesn't add it to the database.
 */
-func EmptyProfile() (profileconf ProfileConf) {
+func EmptyProfile() (profileconf Profile) {
 	profileconf.Ipmi = new(IpmiConf)
 	profileconf.Ipmi.Tags = map[string]string{}
 	profileconf.Kernel = new(KernelConf)
-	profileconf.NetDevs = make(map[string]*NetDevs)
+	profileconf.NetDevs = make(map[string]*NetDev)
 	profileconf.Tags = map[string]string{}
 	return profileconf
 }
@@ -123,7 +123,7 @@ Flattens out a NodeConf, which means if there are no explicit values in *IpmiCon
 or *KernelConf, these pointer will set to nil. This will remove something like
 ipmi: {} from nodes.conf
 */
-func (info *NodeConf) Flatten() {
+func (info *Node) Flatten() {
 	recursiveFlatten(info)
 }
 
@@ -132,7 +132,7 @@ Flattens out a ProfileConf, which means if there are no explicit values in *Ipmi
 or *KernelConf, these pointer will set to nil. This will remove something like
 ipmi: {} from nodes.conf
 */
-func (info *ProfileConf) Flatten() {
+func (info *Profile) Flatten() {
 	recursiveFlatten(info)
 }
 
@@ -296,28 +296,28 @@ Getters for unexported fields
 /*
 Returns the id of the node
 */
-func (node *NodeConf) Id() string {
+func (node *Node) Id() string {
 	return node.id
 }
 
 /*
 Returns the id of the profile
 */
-func (node *ProfileConf) Id() string {
+func (node *Profile) Id() string {
 	return node.id
 }
 
 /*
 Returns if the node is a valid in the database
 */
-func (node *NodeConf) Valid() bool {
+func (node *Node) Valid() bool {
 	return node.valid
 }
 
 /*
 Check if the netdev is the primary one
 */
-func (dev *NetDevs) Primary() bool {
+func (dev *NetDev) Primary() bool {
 	return dev.primary
 }
 
@@ -353,7 +353,7 @@ func cleanList(list []string) (ret []string) {
 Return the ipv4 address and mask in CIDR format. Aimed for the use in
 templates.
 */
-func (netdev *NetDevs) IpCIDR() string {
+func (netdev *NetDev) IpCIDR() string {
 	if netdev.Ipaddr.IsUnspecified() || netdev.Netmask.IsUnspecified() {
 		return ""
 	}
diff --git a/internal/pkg/node/methods_test.go b/internal/pkg/node/methods_test.go
index a629ecb4..860e8257 100644
--- a/internal/pkg/node/methods_test.go
+++ b/internal/pkg/node/methods_test.go
@@ -6,8 +6,8 @@ import (
 )
 
 func Test_Empty(t *testing.T) {
-	var netdev NetDevs
-	var netdevPtr *NetDevs
+	var netdev NetDev
+	var netdevPtr *NetDev
 
 	t.Run("test for empty", func(t *testing.T) {
 		if ObjectIsEmpty(netdev) != true {
diff --git a/internal/pkg/node/modifiers.go b/internal/pkg/node/modifiers.go
index 6abf88a1..1bd5e03b 100644
--- a/internal/pkg/node/modifiers.go
+++ b/internal/pkg/node/modifiers.go
@@ -14,13 +14,13 @@ import (
 /*
 Add a node with the given ID and return a pointer to it
 */
-func (config *NodeYaml) AddNode(nodeID string) (*NodeConf, error) {
+func (config *NodesYaml) AddNode(nodeID string) (*Node, error) {
 	newNode := NewNode(nodeID)
 	wwlog.Verbose("Adding new node: %s", nodeID)
-	if _, ok := config.nodes[nodeID]; ok {
+	if _, ok := config.Nodes[nodeID]; ok {
 		return nil, errors.New("nodename already exists: " + nodeID)
 	} else {
-		config.nodes[nodeID] = &newNode
+		config.Nodes[nodeID] = &newNode
 	}
 	return &newNode, nil
 }
@@ -28,13 +28,13 @@ func (config *NodeYaml) AddNode(nodeID string) (*NodeConf, error) {
 /*
 delete node with the given id
 */
-func (config *NodeYaml) DelNode(nodeID string) error {
-	if _, ok := config.nodes[nodeID]; !ok {
+func (config *NodesYaml) DelNode(nodeID string) error {
+	if _, ok := config.Nodes[nodeID]; !ok {
 		return errors.New("nodename does not exist: " + nodeID)
 	}
 
 	wwlog.Verbose("Deleting node: %s", nodeID)
-	delete(config.nodes, nodeID)
+	delete(config.Nodes, nodeID)
 
 	return nil
 }
@@ -42,8 +42,8 @@ func (config *NodeYaml) DelNode(nodeID string) error {
 /*
 set node for the node with id the values of vals
 */
-func (config *NodeYaml) SetNode(nodeID string, vals NodeConf) error {
-	node, ok := config.nodes[nodeID]
+func (config *NodesYaml) SetNode(nodeID string, vals Node) error {
+	node, ok := config.Nodes[nodeID]
 	if !ok {
 		return ErrNotFound
 	}
@@ -61,8 +61,8 @@ func (config *NodeYaml) SetNode(nodeID string, vals NodeConf) error {
 /*
 set profile for the node with id the values of vals
 */
-func (config *NodeYaml) SetProfile(profileId string, vals ProfileConf) error {
-	profile, ok := config.nodeProfiles[profileId]
+func (config *NodesYaml) SetProfile(profileId string, vals Profile) error {
+	profile, ok := config.NodeProfiles[profileId]
 	if !ok {
 		return ErrNotFound
 	}
@@ -80,13 +80,13 @@ func (config *NodeYaml) SetProfile(profileId string, vals ProfileConf) error {
 /*
 Add a node with the given ID and return a pointer to it
 */
-func (config *NodeYaml) AddProfile(profileId string) (*ProfileConf, error) {
+func (config *NodesYaml) AddProfile(profileId string) (*Profile, error) {
 	profile := EmptyProfile()
 	wwlog.Verbose("adding new profile: %s", profileId)
-	if _, ok := config.nodeProfiles[profileId]; ok {
+	if _, ok := config.NodeProfiles[profileId]; ok {
 		return nil, errors.New("profile already exists: " + profileId)
 	} else {
-		config.nodeProfiles[profileId] = &profile
+		config.NodeProfiles[profileId] = &profile
 	}
 	return &profile, nil
 }
@@ -94,13 +94,13 @@ func (config *NodeYaml) AddProfile(profileId string) (*ProfileConf, error) {
 /*
 delete node with the given id
 */
-func (config *NodeYaml) DelProfile(nodeID string) error {
-	if _, ok := config.nodes[nodeID]; !ok {
+func (config *NodesYaml) DelProfile(nodeID string) error {
+	if _, ok := config.Nodes[nodeID]; !ok {
 		return errors.New("profile does not exist: " + nodeID)
 	}
 
 	wwlog.Verbose("deleting profile: %s", nodeID)
-	delete(config.nodes, nodeID)
+	delete(config.Nodes, nodeID)
 
 	return nil
 }
@@ -108,13 +108,20 @@ func (config *NodeYaml) DelProfile(nodeID string) error {
 /*
 Write the the NodeYaml to disk.
 */
-func (config *NodeYaml) Persist() error {
+func (config *NodesYaml) Persist() error {
+	return config.PersistToFile(ConfigFile)
+}
+
+func (config *NodesYaml) PersistToFile(configFile string) error {
+	if configFile == "" {
+		configFile = ConfigFile
+	}
 	out, dumpErr := config.Dump()
 	if dumpErr != nil {
 		wwlog.Error("%s", dumpErr)
 		return dumpErr
 	}
-	file, err := os.OpenFile(ConfigFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
+	file, err := os.OpenFile(configFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
 	if err != nil {
 		wwlog.Error("%s", err)
 		return err
@@ -124,7 +131,7 @@ func (config *NodeYaml) Persist() error {
 	if err != nil {
 		return err
 	}
-	wwlog.Debug("persisted: %s", ConfigFile)
+	wwlog.Debug("persisted: %s", configFile)
 	return nil
 }
 
@@ -132,12 +139,12 @@ func (config *NodeYaml) Persist() error {
 Dump returns a YAML document representing the nodeDb
 instance. Passes through any errors generated by yaml.Marshal.
 */
-func (config *NodeYaml) Dump() ([]byte, error) {
+func (config *NodesYaml) Dump() ([]byte, error) {
 	// flatten out profiles and nodes
-	for _, val := range config.nodeProfiles {
+	for _, val := range config.NodeProfiles {
 		val.Flatten()
 	}
-	for _, val := range config.nodes {
+	for _, val := range config.Nodes {
 		val.Flatten()
 	}
 	var buf bytes.Buffer
diff --git a/internal/pkg/node/util.go b/internal/pkg/node/util.go
index c3924da1..478e55a4 100644
--- a/internal/pkg/node/util.go
+++ b/internal/pkg/node/util.go
@@ -10,9 +10,9 @@ import (
 /*
 Gets a node by its hardware(mac) address
 */
-func (config *NodeYaml) FindByHwaddr(hwa string) (NodeConf, error) {
+func (config *NodesYaml) FindByHwaddr(hwa string) (Node, error) {
 	if _, err := net.ParseMAC(hwa); err != nil {
-		return NodeConf{}, errors.New("invalid hardware address: " + hwa)
+		return Node{}, errors.New("invalid hardware address: " + hwa)
 	}
 	nodeList, _ := config.FindAllNodes()
 	for _, node := range nodeList {
@@ -23,20 +23,20 @@ func (config *NodeYaml) FindByHwaddr(hwa string) (NodeConf, error) {
 		}
 	}
 
-	return NodeConf{}, ErrNotFound
+	return Node{}, ErrNotFound
 }
 
 /*
 Find a node by its ip address
 */
-func (config *NodeYaml) FindByIpaddr(ipaddr string) (NodeConf, error) {
+func (config *NodesYaml) FindByIpaddr(ipaddr string) (Node, error) {
 	addr := net.ParseIP(ipaddr)
 	if addr == nil {
-		return NodeConf{}, errors.New("invalid IP:" + ipaddr)
+		return Node{}, errors.New("invalid IP:" + ipaddr)
 	}
 	nodeList, err := config.FindAllNodes()
 	if err != nil {
-		return NodeConf{}, err
+		return Node{}, err
 	}
 	for _, node := range nodeList {
 		for _, dev := range node.NetDevs {
@@ -46,7 +46,7 @@ func (config *NodeYaml) FindByIpaddr(ipaddr string) (NodeConf, error) {
 		}
 	}
 
-	return NodeConf{}, ErrNotFound
+	return Node{}, ErrNotFound
 }
 
 /*
diff --git a/internal/pkg/node/util_test.go b/internal/pkg/node/util_test.go
index 54f2dbbc..ecbc4fef 100644
--- a/internal/pkg/node/util_test.go
+++ b/internal/pkg/node/util_test.go
@@ -8,7 +8,7 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
-func NewUtilTestNode() (NodeYaml, error) {
+func NewUtilTestNode() (NodesYaml, error) {
 	var data = `
 nodeprofiles:
   default:
@@ -41,7 +41,7 @@ nodes:
         default: false
         ipaddr: fd1a:2b3c:4d5e:06f0:1234:5678:90ab:cdef
 `
-	var ret NodeYaml
+	var ret NodesYaml
 	err := yaml.Unmarshal([]byte(data), &ret)
 	if err != nil {
 		return ret, err
@@ -62,7 +62,7 @@ func Test_nodeYaml_FindByHwaddr(t *testing.T) {
 	tests := []struct {
 		name string
 		//fields  fields
-		config  NodeYaml
+		config  NodesYaml
 		args    args
 		want    string
 		wantErr bool
@@ -100,7 +100,7 @@ func Test_nodeYaml_FindByIpaddr(t *testing.T) {
 	}
 	tests := []struct {
 		name    string
-		config  NodeYaml
+		config  NodesYaml
 		args    args
 		want    string
 		wantErr bool
diff --git a/internal/pkg/overlay/datastructure.go b/internal/pkg/overlay/datastructure.go
index 8a996023..240fcb2b 100644
--- a/internal/pkg/overlay/datastructure.go
+++ b/internal/pkg/overlay/datastructure.go
@@ -35,17 +35,17 @@ type TemplateStruct struct {
 	Warewulf      warewulfconf.WarewulfConf
 	Tftp          warewulfconf.TFTPConf
 	Paths         warewulfconf.BuildConfig
-	AllNodes      []node.NodeConf
-	node.NodeConf
+	AllNodes      []node.Node
+	node.Node
 	// backward compatiblity
 	Container string
-	ThisNode  *node.NodeConf
+	ThisNode  *node.Node
 }
 
 /*
 Initialize an TemplateStruct with the given node.NodeInfo
 */
-func InitStruct(nodeData node.NodeConf) (TemplateStruct, error) {
+func InitStruct(nodeData node.Node) (TemplateStruct, error) {
 	var tstruct TemplateStruct
 	hostname, _ := os.Hostname()
 	tstruct.BuildHost = hostname
@@ -78,7 +78,7 @@ func InitStruct(nodeData node.NodeConf) (TemplateStruct, error) {
 	dt := time.Now()
 	tstruct.BuildTime = dt.Format("01-02-2006 15:04:05 MST")
 	tstruct.BuildTimeUnix = strconv.FormatInt(dt.Unix(), 10)
-	tstruct.NodeConf.Tags = map[string]string{}
+	tstruct.Node.Tags = map[string]string{}
 	var buf bytes.Buffer
 	enc := gob.NewEncoder(&buf)
 	dec := gob.NewDecoder(&buf)
diff --git a/internal/pkg/overlay/funcmap.go b/internal/pkg/overlay/funcmap.go
index 751a97d0..a9758d76 100644
--- a/internal/pkg/overlay/funcmap.go
+++ b/internal/pkg/overlay/funcmap.go
@@ -106,7 +106,7 @@ func templateContainerFileInclude(containername string, filepath string) string
 
 // don't return an error as we use this function for template evaluation,
 // so error will turn up there as the return string
-func createIgnitionJson(node *node.NodeConf) string {
+func createIgnitionJson(node *node.Node) string {
 	conf, rep, err := node.GetConfig()
 	if len(conf.Storage.Disks) == 0 && len(conf.Storage.Filesystems) == 0 {
 		wwlog.Debug("no disks or filesystems present, don't create a json object")
diff --git a/internal/pkg/overlay/funcmap_test.go b/internal/pkg/overlay/funcmap_test.go
index b68e3bd0..641bc50e 100644
--- a/internal/pkg/overlay/funcmap_test.go
+++ b/internal/pkg/overlay/funcmap_test.go
@@ -9,8 +9,7 @@ import (
 )
 
 func Test_createIgnitionJson(t *testing.T) {
-	node_config := `WW_INTERNAL: 45
-nodes:
+	node_config := `nodes:
   n1:
     disks:
       /dev/vda:
diff --git a/internal/pkg/overlay/overlay.go b/internal/pkg/overlay/overlay.go
index d14747aa..8542b346 100644
--- a/internal/pkg/overlay/overlay.go
+++ b/internal/pkg/overlay/overlay.go
@@ -28,7 +28,7 @@ var (
 /*
 Build all overlays for a node
 */
-func BuildAllOverlays(nodes []node.NodeConf) error {
+func BuildAllOverlays(nodes []node.Node) error {
 	for _, n := range nodes {
 
 		sysOverlays := n.SystemOverlay
@@ -50,7 +50,7 @@ func BuildAllOverlays(nodes []node.NodeConf) error {
 
 // TODO: Add an Overlay Delete for both sourcedir and image
 
-func BuildSpecificOverlays(nodes []node.NodeConf, overlayNames []string) error {
+func BuildSpecificOverlays(nodes []node.Node, overlayNames []string) error {
 	for _, n := range nodes {
 		wwlog.Info("Building overlay for %s: %v", n, overlayNames)
 		for _, overlayName := range overlayNames {
@@ -123,7 +123,7 @@ func OverlayInit(overlayName string) error {
 /*
 Build the given overlays for a node and create a Image for them
 */
-func BuildOverlay(nodeConf node.NodeConf, context string, overlayNames []string) error {
+func BuildOverlay(nodeConf node.Node, context string, overlayNames []string) error {
 	if len(overlayNames) == 0 && context == "" {
 		return nil
 	}
@@ -172,7 +172,7 @@ func BuildOverlay(nodeConf node.NodeConf, context string, overlayNames []string)
 Build the given overlays for a node in the given directory. If the given does not
 exists it will be created.
 */
-func BuildOverlayIndir(nodeData node.NodeConf, overlayNames []string, outputDir string) error {
+func BuildOverlayIndir(nodeData node.Node, overlayNames []string, outputDir string) error {
 	if len(overlayNames) == 0 {
 		return nil
 	}
diff --git a/internal/pkg/overlay/overlay_test.go b/internal/pkg/overlay/overlay_test.go
index d1a02a28..56dab2f4 100644
--- a/internal/pkg/overlay/overlay_test.go
+++ b/internal/pkg/overlay/overlay_test.go
@@ -265,7 +265,7 @@ func Test_BuildAllOverlays(t *testing.T) {
 			defer os.RemoveAll(provisionDir)
 			conf.Paths.WWProvisiondir = provisionDir
 
-			var nodes []node.NodeConf
+			var nodes []node.Node
 			for i, nodeName := range tt.nodes {
 				nodeInfo := node.NewNode(nodeName)
 				if tt.systemOverlays != nil {
@@ -363,7 +363,7 @@ func Test_BuildSpecificOverlays(t *testing.T) {
 			defer os.RemoveAll(provisionDir)
 			conf.Paths.WWProvisiondir = provisionDir
 
-			var nodes []node.NodeConf
+			var nodes []node.Node
 			for _, nodeName := range tt.nodes {
 				nodeInfo := node.NewNode(nodeName)
 				nodes = append(nodes, nodeInfo)
diff --git a/internal/pkg/testenv/testenv.go b/internal/pkg/testenv/testenv.go
index 94d88a83..24ab8e50 100644
--- a/internal/pkg/testenv/testenv.go
+++ b/internal/pkg/testenv/testenv.go
@@ -18,9 +18,8 @@ import (
 	"github.com/warewulf/warewulf/internal/pkg/node"
 )
 
-const initWarewulfConf = `WW_INTERNAL: 0`
-const initNodesConf = `WW_INTERNAL: 45
-nodeprofiles:
+const initWarewulfConf = ``
+const initNodesConf = `nodeprofiles:
   default: {}
 nodes:
   node1: {}
diff --git a/internal/pkg/testenv/testenv_test.go b/internal/pkg/testenv/testenv_test.go
index 46623c96..25ea7929 100644
--- a/internal/pkg/testenv/testenv_test.go
+++ b/internal/pkg/testenv/testenv_test.go
@@ -19,8 +19,7 @@ func Test_Basic(t *testing.T) {
 
 func Test_two_nodes(t *testing.T) {
 	env := New(t)
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 45
-nodeprofiles:
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `nodeprofiles:
   default: {}
 nodes:
   node1: {}
diff --git a/internal/pkg/upgrade/config.go b/internal/pkg/upgrade/config.go
new file mode 100644
index 00000000..ac597911
--- /dev/null
+++ b/internal/pkg/upgrade/config.go
@@ -0,0 +1,243 @@
+package upgrade
+
+import (
+	"gopkg.in/yaml.v3"
+
+	"github.com/warewulf/warewulf/internal/pkg/config"
+)
+
+func ParseConfig(data []byte) (warewulfYaml *WarewulfYaml, err error) {
+	warewulfYaml = new(WarewulfYaml)
+	if err = yaml.Unmarshal(data, warewulfYaml); err != nil {
+		return warewulfYaml, err
+	}
+	return warewulfYaml, nil
+}
+
+type WarewulfYaml struct {
+	WWInternal      string        `yaml:"WW_INTERNAL"`
+	Comment         string        `yaml:"comment"`
+	Ipaddr          string        `yaml:"ipaddr"`
+	Ipaddr6         string        `yaml:"ipaddr6"`
+	Netmask         string        `yaml:"netmask"`
+	Network         string        `yaml:"network"`
+	Ipv6net         string        `yaml:"ipv6net"`
+	Fqdn            string        `yaml:"fqdn"`
+	Warewulf        *WarewulfConf `yaml:"warewulf"`
+	DHCP            *DHCPConf     `yaml:"dhcp"`
+	TFTP            *TFTPConf     `yaml:"tftp"`
+	NFS             *NFSConf      `yaml:"nfs"`
+	SSH             *SSHConf      `yaml:"ssh"`
+	MountsContainer []*MountEntry `yaml:"container mounts"`
+	Paths           *BuildConfig  `yaml:"paths"`
+	WWClient        *WWClientConf `yaml:"wwclient"`
+}
+
+func (this *WarewulfYaml) Upgrade() (upgraded *config.WarewulfYaml) {
+	upgraded = new(config.WarewulfYaml)
+	if this.WWInternal != "" {
+		logIgnore("WW_INTERNAL", this.WWInternal, "obsolete")
+	}
+	upgraded.Comment = this.Comment
+	upgraded.Ipaddr = this.Ipaddr
+	upgraded.Ipaddr6 = this.Ipaddr6
+	upgraded.Netmask = this.Netmask
+	upgraded.Network = this.Network
+	upgraded.Ipv6net = this.Ipv6net
+	upgraded.Fqdn = this.Fqdn
+	if this.Warewulf != nil {
+		upgraded.Warewulf = this.Warewulf.Upgrade()
+	}
+	if this.DHCP != nil {
+		upgraded.DHCP = this.DHCP.Upgrade()
+	}
+	if this.TFTP != nil {
+		upgraded.TFTP = this.TFTP.Upgrade()
+	}
+	if this.NFS != nil {
+		upgraded.NFS = this.NFS.Upgrade()
+	}
+	if this.SSH != nil {
+		upgraded.SSH = this.SSH.Upgrade()
+	}
+	upgraded.MountsContainer = make([]*config.MountEntry, 0)
+	for _, mount := range this.MountsContainer {
+		upgraded.MountsContainer = append(upgraded.MountsContainer, mount.Upgrade())
+	}
+	if this.Paths != nil {
+		upgraded.Paths = this.Paths.Upgrade()
+	}
+	if this.WWClient != nil {
+		upgraded.WWClient = this.WWClient.Upgrade()
+	}
+	return upgraded
+}
+
+type WarewulfConf struct {
+	Port              int    `yaml:"port"`
+	Secure            *bool  `yaml:"secure"`
+	UpdateInterval    int    `yaml:"update interval"`
+	AutobuildOverlays *bool  `yaml:"autobuild overlays"`
+	EnableHostOverlay *bool  `yaml:"host overlay"`
+	Syslog            *bool  `yaml:"syslog"`
+	DataStore         string `yaml:"datastore"`
+	GrubBoot          *bool  `yaml:"grubboot"`
+}
+
+func (this *WarewulfConf) Upgrade() (upgraded *config.WarewulfConf) {
+	upgraded = new(config.WarewulfConf)
+	upgraded.Port = this.Port
+	upgraded.SecureP = this.Secure
+	upgraded.UpdateInterval = this.UpdateInterval
+	upgraded.AutobuildOverlaysP = this.AutobuildOverlays
+	upgraded.EnableHostOverlayP = this.EnableHostOverlay
+	upgraded.SyslogP = this.Syslog
+	upgraded.DataStore = this.DataStore
+	upgraded.GrubBootP = this.GrubBoot
+	return upgraded
+}
+
+type DHCPConf struct {
+	Enabled     *bool  `yaml:"enabled"`
+	Template    string `yaml:"template"`
+	RangeStart  string `yaml:"range start"`
+	RangeEnd    string `yaml:"range end"`
+	SystemdName string `yaml:"systemd name"`
+}
+
+func (this *DHCPConf) Upgrade() (upgraded *config.DHCPConf) {
+	upgraded = new(config.DHCPConf)
+	upgraded.EnabledP = this.Enabled
+	upgraded.Template = this.Template
+	upgraded.RangeStart = this.RangeStart
+	upgraded.RangeEnd = this.RangeEnd
+	upgraded.SystemdName = this.SystemdName
+	return upgraded
+}
+
+type TFTPConf struct {
+	Enabled      *bool             `yaml:"enabled"`
+	TftpRoot     string            `yaml:"tftproot"`
+	SystemdName  string            `yaml:"systemd name"`
+	IpxeBinaries map[string]string `yaml:"ipxe"`
+}
+
+func (this *TFTPConf) Upgrade() (upgraded *config.TFTPConf) {
+	upgraded = new(config.TFTPConf)
+	upgraded.EnabledP = this.Enabled
+	upgraded.TftpRoot = this.TftpRoot
+	upgraded.SystemdName = this.SystemdName
+	upgraded.IpxeBinaries = make(map[string]string)
+	for name, binary := range this.IpxeBinaries {
+		upgraded.IpxeBinaries[name] = binary
+	}
+	return upgraded
+}
+
+type NFSConf struct {
+	Enabled         *bool            `yaml:"enabled"`
+	Exports         []string         `yaml:"exports"`
+	ExportsExtended []*NFSExportConf `yaml:"export paths"`
+	SystemdName     string           `yaml:"systemd name"`
+}
+
+func (this *NFSConf) Upgrade() (upgraded *config.NFSConf) {
+	upgraded = new(config.NFSConf)
+	upgraded.EnabledP = this.Enabled
+	upgraded.ExportsExtended = make([]*config.NFSExportConf, 0)
+	for _, export := range this.Exports {
+		extendedExport := new(config.NFSExportConf)
+		extendedExport.Path = export
+		upgraded.ExportsExtended = append(upgraded.ExportsExtended, extendedExport)
+	}
+	for _, export := range this.ExportsExtended {
+		upgraded.ExportsExtended = append(upgraded.ExportsExtended, export.Upgrade())
+	}
+	upgraded.SystemdName = this.SystemdName
+	return upgraded
+}
+
+type NFSExportConf struct {
+	Path          string `yaml:"path"`
+	ExportOptions string `yaml:"export options"`
+	MountOptions  string `yaml:"mount options"`
+	Mount         *bool  `yaml:"mount"`
+}
+
+func (this *NFSExportConf) Upgrade() (upgraded *config.NFSExportConf) {
+	upgraded = new(config.NFSExportConf)
+	upgraded.Path = this.Path
+	upgraded.ExportOptions = this.ExportOptions
+	upgraded.MountOptions = this.MountOptions
+	upgraded.MountP = this.Mount
+	return upgraded
+}
+
+type SSHConf struct {
+	KeyTypes []string `yaml:"key types"`
+}
+
+func (this *SSHConf) Upgrade() (upgraded *config.SSHConf) {
+	upgraded = new(config.SSHConf)
+	upgraded.KeyTypes = append([]string{}, this.KeyTypes...)
+	return upgraded
+}
+
+type MountEntry struct {
+	Source   string `yaml:"source"`
+	Dest     string `yaml:"dest"`
+	ReadOnly *bool  `yaml:"readonly"`
+	Options  string `yaml:"options"`
+	Copy     *bool  `yaml:"copy"`
+}
+
+func (this *MountEntry) Upgrade() (upgraded *config.MountEntry) {
+	upgraded = new(config.MountEntry)
+	upgraded.Source = this.Source
+	upgraded.Dest = this.Dest
+	upgraded.ReadOnlyP = this.ReadOnly
+	upgraded.Options = this.Options
+	upgraded.CopyP = this.Copy
+	return upgraded
+}
+
+type BuildConfig struct {
+	Bindir         string
+	Sysconfdir     string
+	Localstatedir  string
+	Cachedir       string
+	Ipxesource     string
+	Srvdir         string
+	Firewallddir   string
+	Systemddir     string
+	WWOverlaydir   string
+	WWChrootdir    string
+	WWProvisiondir string
+	WWClientdir    string
+}
+
+func (this *BuildConfig) Upgrade() (upgraded *config.BuildConfig) {
+	upgraded = new(config.BuildConfig)
+	upgraded.Bindir = this.Bindir
+	upgraded.Sysconfdir = this.Sysconfdir
+	upgraded.Localstatedir = this.Localstatedir
+	upgraded.Cachedir = this.Cachedir
+	upgraded.Ipxesource = this.Ipxesource
+	upgraded.Srvdir = this.Srvdir
+	upgraded.Firewallddir = this.Firewallddir
+	upgraded.WWOverlaydir = this.WWOverlaydir
+	upgraded.WWChrootdir = this.WWChrootdir
+	upgraded.WWProvisiondir = this.WWProvisiondir
+	upgraded.WWClientdir = this.WWClientdir
+	return upgraded
+}
+
+type WWClientConf struct {
+	Port uint16 `yaml:"port"`
+}
+
+func (this *WWClientConf) Upgrade() (upgraded *config.WWClientConf) {
+	upgraded = new(config.WWClientConf)
+	upgraded.Port = this.Port
+	return upgraded
+}
diff --git a/internal/pkg/upgrade/config_test.go b/internal/pkg/upgrade/config_test.go
new file mode 100644
index 00000000..cd29511d
--- /dev/null
+++ b/internal/pkg/upgrade/config_test.go
@@ -0,0 +1,422 @@
+package upgrade
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var configUpgradeTests = []struct {
+	name         string
+	legacyYaml   string
+	upgradedYaml string
+}{
+	{
+		name:         "empty",
+		legacyYaml:   ``,
+		upgradedYaml: `{}`,
+	},
+	{
+		name: "v4.0.0",
+		legacyYaml: `
+ipaddr: 192.168.1.1
+netmask: 255.255.255.0
+warewulf:
+  port: 9873
+  secure: true
+  update interval: 60
+dhcp:
+  enabled: true
+  range start: 192.168.1.150
+  range end: 192.168.1.200
+  template: default
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  tftproot: /var/lib/tftpboot
+  systemd name: tftp
+nfs:
+  systemd name: nfs-server
+  exports:
+  - /home
+  - /var/warewulf
+`,
+		upgradedYaml: `
+ipaddr: 192.168.1.1
+netmask: 255.255.255.0
+warewulf:
+  port: 9873
+  secure: true
+  update interval: 60
+dhcp:
+  enabled: true
+  template: default
+  range start: 192.168.1.150
+  range end: 192.168.1.200
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  tftproot: /var/lib/tftpboot
+  systemd name: tftp
+nfs:
+  export paths:
+    - path: /home
+    - path: /var/warewulf
+  systemd name: nfs-server
+`,
+	},
+	{
+		name: "v4.1.0",
+		legacyYaml: `
+ipaddr: 192.168.1.1
+netmask: 255.255.255.0
+warewulf:
+  port: 9873
+  secure: true
+  update interval: 60
+dhcp:
+  enabled: true
+  range start: 192.168.1.150
+  range end: 192.168.1.200
+  template: default
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  tftproot: /var/lib/tftpboot
+  systemd name: tftp
+nfs:
+  systemd name: nfs-server
+  exports:
+  - /home
+  - /var/warewulf
+`,
+		upgradedYaml: `
+ipaddr: 192.168.1.1
+netmask: 255.255.255.0
+warewulf:
+  port: 9873
+  secure: true
+  update interval: 60
+dhcp:
+  enabled: true
+  template: default
+  range start: 192.168.1.150
+  range end: 192.168.1.200
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  tftproot: /var/lib/tftpboot
+  systemd name: tftp
+nfs:
+  export paths:
+    - path: /home
+    - path: /var/warewulf
+  systemd name: nfs-server
+`,
+	},
+	{
+		name: "v4.2.0",
+		legacyYaml: `
+ipaddr: 192.168.200.1
+netmask: 255.255.255.0
+warewulf:
+  port: 9873
+  secure: true
+  autobuild overlays: true
+  update interval: 60
+  syslog: false
+dhcp:
+  enabled: true
+  range start: 192.168.200.50
+  range end: 192.168.200.99
+  template: default
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  tftproot: /var/lib/tftpboot
+  systemd name: tftp
+nfs:
+  systemd name: nfs-server
+  exports:
+  - /home
+  - /var/warewulf
+`,
+		upgradedYaml: `
+ipaddr: 192.168.200.1
+netmask: 255.255.255.0
+warewulf:
+  port: 9873
+  secure: true
+  update interval: 60
+  autobuild overlays: true
+  syslog: false
+dhcp:
+  enabled: true
+  template: default
+  range start: 192.168.200.50
+  range end: 192.168.200.99
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  tftproot: /var/lib/tftpboot
+  systemd name: tftp
+nfs:
+  export paths:
+    - path: /home
+    - path: /var/warewulf
+  systemd name: nfs-server
+`,
+	},
+	{
+		name: "v4.3.0",
+		legacyYaml: `
+WW_INTERNAL: 43
+ipaddr: 192.168.200.1
+netmask: 255.255.255.0
+network: 192.168.200.0
+warewulf:
+  port: 9873
+  secure: false
+  update interval: 60
+  autobuild overlays: true
+  host overlay: true
+  syslog: false
+  datastore: ""
+dhcp:
+  enabled: true
+  template: default
+  range start: 192.168.200.50
+  range end: 192.168.200.99
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  tftproot: ""
+  systemd name: tftp
+nfs:
+  enabled: true
+  export paths:
+  - path: /home
+    export options: rw,sync
+    mount options: defaults
+    mount: true
+  - path: /opt
+    export options: ro,sync,no_root_squash
+    mount options: defaults
+    mount: false
+  systemd name: nfs-server
+`,
+		upgradedYaml: `
+ipaddr: 192.168.200.1
+netmask: 255.255.255.0
+network: 192.168.200.0
+warewulf:
+  port: 9873
+  secure: false
+  update interval: 60
+  autobuild overlays: true
+  host overlay: true
+  syslog: false
+dhcp:
+  enabled: true
+  template: default
+  range start: 192.168.200.50
+  range end: 192.168.200.99
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  systemd name: tftp
+nfs:
+  enabled: true
+  export paths:
+    - path: /home
+      export options: rw,sync
+      mount options: defaults
+      mount: true
+    - path: /opt
+      export options: ro,sync,no_root_squash
+      mount options: defaults
+      mount: false
+  systemd name: nfs-server
+`,
+	},
+	{
+		name: "v4.4.1",
+		legacyYaml: `
+WW_INTERNAL: 43
+ipaddr: 192.168.200.1
+netmask: 255.255.255.0
+network: 192.168.200.0
+warewulf:
+  port: 9873
+  secure: false
+  update interval: 60
+  autobuild overlays: true
+  host overlay: true
+  syslog: false
+dhcp:
+  enabled: true
+  range start: 192.168.200.50
+  range end: 192.168.200.99
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  systemd name: tftp
+nfs:
+  enabled: true
+  export paths:
+  - path: /home
+    export options: rw,sync
+    mount options: defaults
+    mount: true
+  - path: /opt
+    export options: ro,sync,no_root_squash
+    mount options: defaults
+    mount: false
+  systemd name: nfs-server
+`,
+		upgradedYaml: `
+ipaddr: 192.168.200.1
+netmask: 255.255.255.0
+network: 192.168.200.0
+warewulf:
+  port: 9873
+  secure: false
+  update interval: 60
+  autobuild overlays: true
+  host overlay: true
+  syslog: false
+dhcp:
+  enabled: true
+  range start: 192.168.200.50
+  range end: 192.168.200.99
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  systemd name: tftp
+nfs:
+  enabled: true
+  export paths:
+    - path: /home
+      export options: rw,sync
+      mount options: defaults
+      mount: true
+    - path: /opt
+      export options: ro,sync,no_root_squash
+      mount options: defaults
+      mount: false
+  systemd name: nfs-server
+`,
+	},
+	{
+		name: "v4.5.8",
+		legacyYaml: `
+WW_INTERNAL: 45
+ipaddr: 10.0.0.1
+netmask: 255.255.252.0
+network: 10.0.0.0
+warewulf:
+  port: 9873
+  secure: false
+  update interval: 60
+  autobuild overlays: true
+  host overlay: true
+  syslog: false
+dhcp:
+  enabled: true
+  range start: 10.0.1.1
+  range end: 10.0.1.255
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  systemd name: tftp
+  ipxe:
+    00:09: ipxe-snponly-x86_64.efi
+    00:00: undionly.kpxe
+    00:0B: arm64-efi/snponly.efi
+    00:07: ipxe-snponly-x86_64.efi
+nfs:
+  enabled: true
+  export paths:
+  - path: /home
+    export options: rw,sync
+    mount options: defaults
+    mount: true
+  - path: /opt
+    export options: ro,sync,no_root_squash
+    mount options: defaults
+    mount: false
+  systemd name: nfs-server
+container mounts:
+  - source: /etc/resolv.conf
+    dest: /etc/resolv.conf
+    readonly: true
+ssh:
+  key types:
+    - rsa
+    - dsa
+    - ecdsa
+    - ed25519
+`,
+		upgradedYaml: `
+ipaddr: 10.0.0.1
+netmask: 255.255.252.0
+network: 10.0.0.0
+warewulf:
+  port: 9873
+  secure: false
+  update interval: 60
+  autobuild overlays: true
+  host overlay: true
+  syslog: false
+dhcp:
+  enabled: true
+  range start: 10.0.1.1
+  range end: 10.0.1.255
+  systemd name: dhcpd
+tftp:
+  enabled: true
+  systemd name: tftp
+  ipxe:
+    00:0B: arm64-efi/snponly.efi
+    "00:00": undionly.kpxe
+    "00:07": ipxe-snponly-x86_64.efi
+    "00:09": ipxe-snponly-x86_64.efi
+nfs:
+  enabled: true
+  export paths:
+    - path: /home
+      export options: rw,sync
+      mount options: defaults
+      mount: true
+    - path: /opt
+      export options: ro,sync,no_root_squash
+      mount options: defaults
+      mount: false
+  systemd name: nfs-server
+ssh:
+  key types:
+    - rsa
+    - dsa
+    - ecdsa
+    - ed25519
+container mounts:
+  - source: /etc/resolv.conf
+    dest: /etc/resolv.conf
+    readonly: true
+`,
+	},
+}
+
+func Test_UpgradeConfig(t *testing.T) {
+	for _, tt := range configUpgradeTests {
+		t.Run(tt.name, func(t *testing.T) {
+			legacy, err := ParseConfig([]byte(tt.legacyYaml))
+			assert.NoError(t, err)
+			upgraded := legacy.Upgrade()
+			upgradedYaml, err := upgraded.Dump()
+			assert.NoError(t, err)
+			assert.Equal(t, strings.TrimSpace(tt.upgradedYaml), strings.TrimSpace(string(upgradedYaml)))
+		})
+	}
+}
diff --git a/internal/pkg/upgrade/logging.go b/internal/pkg/upgrade/logging.go
new file mode 100644
index 00000000..68b1e01d
--- /dev/null
+++ b/internal/pkg/upgrade/logging.go
@@ -0,0 +1,15 @@
+package upgrade
+
+import (
+	"github.com/warewulf/warewulf/internal/pkg/wwlog"
+)
+
+func logIgnore(name string, value interface{}, reason string) {
+	wwlog.Warn("ignore: %s: %v (%s)", name, value, reason)
+}
+
+func warnError(err error) {
+	if err != nil {
+		wwlog.Warn("%s", err)
+	}
+}
diff --git a/internal/pkg/upgrade/node.go b/internal/pkg/upgrade/node.go
new file mode 100644
index 00000000..d02e1a5f
--- /dev/null
+++ b/internal/pkg/upgrade/node.go
@@ -0,0 +1,640 @@
+package upgrade
+
+import (
+	"net"
+	"strconv"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+
+	"github.com/warewulf/warewulf/internal/pkg/node"
+	"github.com/warewulf/warewulf/internal/pkg/util"
+	"github.com/warewulf/warewulf/internal/pkg/wwlog"
+)
+
+var wwinitSplitOverlays = []string{
+	"wwinit",
+	"wwclient",
+	"fstab",
+	"hostname",
+	"ssh.host_keys",
+	"issue",
+	"resolv",
+	"udev.netname",
+	"systemd.netname",
+	"ifcfg",
+	"NetworkManager",
+	"debian.interfaces",
+	"wicked",
+	"ignition",
+}
+
+var genericSplitOverlays = []string{
+	"hosts",
+	"ssh.authorized_keys",
+	"syncuser",
+}
+
+func ParseNodes(data []byte) (nodesYaml *NodesYaml, err error) {
+	nodesYaml = new(NodesYaml)
+	if err = yaml.Unmarshal(data, nodesYaml); err != nil {
+		return nodesYaml, err
+	}
+	return nodesYaml, nil
+}
+
+type NodesYaml struct {
+	WWInternal   string `yaml:"WW_INTERNAL"`
+	NodeProfiles map[string]*Profile
+	Nodes        map[string]*Node
+}
+
+func (this *NodesYaml) Upgrade(addDefaults bool, replaceOverlays bool) (upgraded *node.NodesYaml) {
+	upgraded = new(node.NodesYaml)
+	upgraded.NodeProfiles = make(map[string]*node.Profile)
+	upgraded.Nodes = make(map[string]*node.Node)
+	if this.WWInternal != "" {
+		logIgnore("WW_INTERNAL", this.WWInternal, "obsolete")
+	}
+	for name, profile := range this.NodeProfiles {
+		upgraded.NodeProfiles[name] = profile.Upgrade(addDefaults, replaceOverlays)
+	}
+	for name, node := range this.Nodes {
+		upgraded.Nodes[name] = node.Upgrade(addDefaults, replaceOverlays)
+		if addDefaults && !util.InSlice(upgraded.Nodes[name].Profiles, "default") {
+			wwlog.Warn("node %s does not include the default profile: verify default settings manually", name)
+		}
+	}
+	if addDefaults {
+		if _, ok := upgraded.NodeProfiles["default"]; !ok {
+			upgraded.NodeProfiles["default"] = new(node.Profile)
+			upgraded.NodeProfiles["default"].Kernel = new(node.KernelConf)
+		}
+		defaultProfile := upgraded.NodeProfiles["default"]
+		if len(defaultProfile.SystemOverlay) == 0 {
+			defaultProfile.SystemOverlay = append(
+				defaultProfile.SystemOverlay, wwinitSplitOverlays...)
+		}
+		if len(defaultProfile.RuntimeOverlay) == 0 {
+			defaultProfile.RuntimeOverlay = append(
+				defaultProfile.RuntimeOverlay, genericSplitOverlays...)
+		}
+		if defaultProfile.Kernel.Args == "" {
+			defaultProfile.Kernel.Args = "quiet crashkernel=no vga=791 net.naming-scheme=v238"
+		}
+		if defaultProfile.Init == "" {
+			defaultProfile.Init = "/sbin/init"
+		}
+		if defaultProfile.Root == "" {
+			defaultProfile.Root = "initramfs"
+		}
+		if defaultProfile.Ipxe == "" {
+			defaultProfile.Ipxe = "default"
+		}
+	}
+	return upgraded
+}
+
+type Node struct {
+	Profile `yaml:"-,inline"`
+}
+
+func (this *Node) Upgrade(addDefaults bool, replaceOverlays bool) (upgraded *node.Node) {
+	upgraded = new(node.Node)
+	upgraded.Tags = make(map[string]string)
+	upgraded.Disks = make(map[string]*node.Disk)
+	upgraded.FileSystems = make(map[string]*node.FileSystem)
+	upgraded.Ipmi = new(node.IpmiConf)
+	upgraded.Kernel = new(node.KernelConf)
+	upgraded.NetDevs = make(map[string]*node.NetDev)
+	upgraded.AssetKey = this.AssetKey
+	upgraded.ClusterName = this.ClusterName
+	upgraded.Comment = this.Comment
+	upgraded.ContainerName = this.ContainerName
+	if this.Disabled != "" {
+		logIgnore("Disabled", this.Disabled, "obsolete")
+	}
+	if this.Discoverable != "" {
+		warnError(upgraded.Discoverable.Set(this.Discoverable))
+	}
+	if this.Disks != nil {
+		for name, disk := range this.Disks {
+			upgraded.Disks[name] = disk.Upgrade()
+		}
+	}
+	if this.FileSystems != nil {
+		for name, fileSystem := range this.FileSystems {
+			upgraded.FileSystems[name] = fileSystem.Upgrade()
+		}
+	}
+	upgraded.Init = this.Init
+	if this.Ipmi != nil {
+		upgraded.Ipmi = this.Ipmi.Upgrade()
+	} else {
+		upgraded.Ipmi = new(node.IpmiConf)
+	}
+	if upgraded.Ipmi.EscapeChar == "" {
+		upgraded.Ipmi.EscapeChar = this.IpmiEscapeChar
+	}
+	if upgraded.Ipmi.Gateway.Equal(net.IP{}) {
+		upgraded.Ipmi.Gateway = net.ParseIP(this.IpmiGateway)
+	}
+	if upgraded.Ipmi.Interface == "" {
+		upgraded.Ipmi.Interface = this.IpmiInterface
+	}
+	if upgraded.Ipmi.Ipaddr.Equal(net.IP{}) {
+		upgraded.Ipmi.Ipaddr = net.ParseIP(this.IpmiIpaddr)
+	}
+	if upgraded.Ipmi.Netmask.Equal(net.IP{}) {
+		upgraded.Ipmi.Netmask = net.ParseIP(this.IpmiNetmask)
+	}
+	if upgraded.Ipmi.Password == "" {
+		upgraded.Ipmi.Password = this.IpmiPassword
+	}
+	if upgraded.Ipmi.Port == "" {
+		upgraded.Ipmi.Port = this.IpmiPort
+	}
+	if upgraded.Ipmi.UserName == "" {
+		upgraded.Ipmi.UserName = this.IpmiUserName
+	}
+	if upgraded.Ipmi.Write == "" && this.IpmiWrite != "" {
+		warnError(upgraded.Ipmi.Write.Set(this.IpmiWrite))
+	}
+	upgraded.Ipxe = this.Ipxe
+	if this.Kernel != nil {
+		upgraded.Kernel = this.Kernel.Upgrade()
+	} else {
+		upgraded.Kernel = new(node.KernelConf)
+	}
+	if upgraded.Kernel.Args == "" {
+		upgraded.Kernel.Args = this.KernelArgs
+	}
+	if upgraded.Kernel.Override == "" {
+		upgraded.Kernel.Override = this.KernelOverride
+	}
+	if upgraded.Kernel.Version == "" {
+		upgraded.Kernel.Version = this.KernelVersion
+	}
+	if this.Keys != nil {
+		for key, value := range this.Keys {
+			upgraded.Tags[key] = value
+		}
+	}
+	if this.NetDevs != nil {
+		for name, netDev := range this.NetDevs {
+			upgraded.NetDevs[name] = netDev.Upgrade(addDefaults)
+		}
+	}
+	if this.PrimaryNetDev != "" {
+		upgraded.PrimaryNetDev = this.PrimaryNetDev
+	} else {
+		for name, netDev := range this.NetDevs {
+			if b, _ := strconv.ParseBool(netDev.Primary); b {
+				upgraded.PrimaryNetDev = name
+				break
+			} else if b, _ := strconv.ParseBool(netDev.Default); b {
+				upgraded.PrimaryNetDev = name
+				break
+			}
+		}
+	}
+	upgraded.Profiles = append(upgraded.Profiles, this.Profiles...)
+	if addDefaults {
+		if len(upgraded.Profiles) == 0 {
+			upgraded.Profiles = append(upgraded.Profiles, "default")
+		}
+	}
+	upgraded.Root = this.Root
+	if this.RuntimeOverlay != nil {
+		switch overlay := this.RuntimeOverlay.(type) {
+		case string:
+			upgraded.RuntimeOverlay = append(upgraded.RuntimeOverlay, strings.Split(overlay, ",")...)
+		case []interface{}:
+			for _, each := range overlay {
+				upgraded.RuntimeOverlay = append(upgraded.RuntimeOverlay, each.(string))
+			}
+		default:
+			wwlog.Error("unparsable RuntimeOverlay: %v", overlay)
+		}
+	}
+	if this.SystemOverlay != nil {
+		switch overlay := this.SystemOverlay.(type) {
+		case string:
+			upgraded.SystemOverlay = append(upgraded.SystemOverlay, strings.Split(overlay, ",")...)
+		case []interface{}:
+			for _, each := range overlay {
+				upgraded.SystemOverlay = append(upgraded.SystemOverlay, each.(string))
+			}
+		default:
+			wwlog.Error("unparsable SystemOverlay: %v", overlay)
+		}
+	}
+	if replaceOverlays {
+		if indexOf(upgraded.SystemOverlay, "wwinit") != -1 {
+			upgraded.SystemOverlay = replaceSliceElement(
+				upgraded.SystemOverlay,
+				indexOf(upgraded.SystemOverlay, "wwinit"),
+				wwinitSplitOverlays)
+		}
+		if indexOf(upgraded.RuntimeOverlay, "generic") != -1 {
+			upgraded.RuntimeOverlay = replaceSliceElement(
+				upgraded.RuntimeOverlay,
+				indexOf(upgraded.RuntimeOverlay, "generic"),
+				genericSplitOverlays)
+		}
+	}
+	if this.Tags != nil {
+		for key, value := range this.Tags {
+			upgraded.Tags[key] = value
+		}
+	}
+	for _, tag := range this.TagsDel {
+		delete(upgraded.Tags, tag)
+	}
+	return
+}
+
+type Profile struct {
+	AssetKey       string                 `yaml:"asset key,omitempty"`
+	ClusterName    string                 `yaml:"cluster name,omitempty"`
+	Comment        string                 `yaml:"comment,omitempty"`
+	ContainerName  string                 `yaml:"container name,omitempty"`
+	Disabled       string                 `yaml:"disabled,omitempty"`
+	Discoverable   string                 `yaml:"discoverable,omitempty"`
+	Disks          map[string]*Disk       `yaml:"disks,omitempty"`
+	FileSystems    map[string]*FileSystem `yaml:"filesystems,omitempty"`
+	Init           string                 `yaml:"init,omitempty"`
+	Ipmi           *IpmiConf              `yaml:"ipmi,omitempty"`
+	IpmiEscapeChar string                 `yaml:"ipmi escapechar,omitempty"`
+	IpmiGateway    string                 `yaml:"ipmi gateway,omitempty"`
+	IpmiInterface  string                 `yaml:"ipmi interface,omitempty"`
+	IpmiIpaddr     string                 `yaml:"ipmi ipaddr,omitempty"`
+	IpmiNetmask    string                 `yaml:"ipmi netmask,omitempty"`
+	IpmiPassword   string                 `yaml:"ipmi password,omitempty"`
+	IpmiPort       string                 `yaml:"ipmi port,omitempty"`
+	IpmiUserName   string                 `yaml:"ipmi username,omitempty"`
+	IpmiWrite      string                 `yaml:"ipmi write,omitempty"`
+	Ipxe           string                 `yaml:"ipxe template,omitempty"`
+	Kernel         *KernelConf            `yaml:"kernel,omitempty"`
+	KernelArgs     string                 `yaml:"kernel args,omitempty"`
+	KernelOverride string                 `yaml:"kernel override,omitempty"`
+	KernelVersion  string                 `yaml:"kernel version,omitempty"`
+	Keys           map[string]string      `yaml:"keys,omitempty"`
+	NetDevs        map[string]*NetDev     `yaml:"network devices,omitempty"`
+	PrimaryNetDev  string                 `yaml:"primary network,omitempty"`
+	Profiles       []string               `yaml:"profiles,omitempty"`
+	Root           string                 `yaml:"root,omitempty"`
+	RuntimeOverlay interface{}            `yaml:"runtime overlay,omitempty"`
+	SystemOverlay  interface{}            `yaml:"system overlay,omitempty"`
+	Tags           map[string]string      `yaml:"tags,omitempty"`
+	TagsDel        []string               `yaml:"tagsdel,omitempty"`
+}
+
+func (this *Profile) Upgrade(addDefaults bool, replaceOverlays bool) (upgraded *node.Profile) {
+	upgraded = new(node.Profile)
+	upgraded.Tags = make(map[string]string)
+	upgraded.Disks = make(map[string]*node.Disk)
+	upgraded.FileSystems = make(map[string]*node.FileSystem)
+	upgraded.Kernel = new(node.KernelConf)
+	upgraded.NetDevs = make(map[string]*node.NetDev)
+	if this.AssetKey != "" {
+		logIgnore("AssetKey", this.AssetKey, "invalid for profiles")
+	}
+	upgraded.ClusterName = this.ClusterName
+	upgraded.Comment = this.Comment
+	upgraded.ContainerName = this.ContainerName
+	if this.Disabled != "" {
+		logIgnore("Disabled", this.Disabled, "obsolete")
+	}
+	if this.Discoverable != "" {
+		logIgnore("Discoverable", this.Discoverable, "invalid for profiles")
+	}
+	if this.Disks != nil {
+		for name, disk := range this.Disks {
+			upgraded.Disks[name] = disk.Upgrade()
+		}
+	}
+	if this.FileSystems != nil {
+		for name, fileSystem := range this.FileSystems {
+			upgraded.FileSystems[name] = fileSystem.Upgrade()
+		}
+	}
+	upgraded.Init = this.Init
+	upgraded.Ipmi = new(node.IpmiConf)
+	if this.Ipmi != nil {
+		upgraded.Ipmi = this.Ipmi.Upgrade()
+	} else {
+		upgraded.Ipmi = new(node.IpmiConf)
+	}
+	if upgraded.Ipmi.EscapeChar == "" {
+		upgraded.Ipmi.EscapeChar = this.IpmiEscapeChar
+	}
+	if upgraded.Ipmi.Gateway.Equal(net.IP{}) {
+		upgraded.Ipmi.Gateway = net.ParseIP(this.IpmiGateway)
+	}
+	if upgraded.Ipmi.Interface == "" {
+		upgraded.Ipmi.Interface = this.IpmiInterface
+	}
+	if upgraded.Ipmi.Ipaddr.Equal(net.IP{}) {
+		upgraded.Ipmi.Ipaddr = net.ParseIP(this.IpmiIpaddr)
+	}
+	if upgraded.Ipmi.Netmask.Equal(net.IP{}) {
+		upgraded.Ipmi.Netmask = net.ParseIP(this.IpmiNetmask)
+	}
+	if upgraded.Ipmi.Password == "" {
+		upgraded.Ipmi.Password = this.IpmiPassword
+	}
+	if upgraded.Ipmi.Port == "" {
+		upgraded.Ipmi.Port = this.IpmiPort
+	}
+	if upgraded.Ipmi.UserName == "" {
+		upgraded.Ipmi.UserName = this.IpmiUserName
+	}
+	if upgraded.Ipmi.Write == "" && this.IpmiWrite != "" {
+		warnError(upgraded.Ipmi.Write.Set(this.IpmiWrite))
+	}
+	upgraded.Ipxe = this.Ipxe
+	if this.Kernel != nil {
+		upgraded.Kernel = this.Kernel.Upgrade()
+	} else {
+		upgraded.Kernel = new(node.KernelConf)
+	}
+	if upgraded.Kernel.Args == "" {
+		upgraded.Kernel.Args = this.KernelArgs
+	}
+	if upgraded.Kernel.Override == "" {
+		upgraded.Kernel.Override = this.KernelOverride
+	}
+	if upgraded.Kernel.Version == "" {
+		upgraded.Kernel.Version = this.KernelVersion
+	}
+	if this.Keys != nil {
+		for key, value := range this.Keys {
+			upgraded.Tags[key] = value
+		}
+	}
+	if this.NetDevs != nil {
+		for name, netDev := range this.NetDevs {
+			upgraded.NetDevs[name] = netDev.Upgrade(addDefaults)
+		}
+	}
+	if this.PrimaryNetDev != "" {
+		upgraded.PrimaryNetDev = this.PrimaryNetDev
+	} else {
+		for name, netDev := range this.NetDevs {
+			if b, _ := strconv.ParseBool(netDev.Primary); b {
+				upgraded.PrimaryNetDev = name
+				break
+			} else if b, _ := strconv.ParseBool(netDev.Default); b {
+				upgraded.PrimaryNetDev = name
+				break
+			}
+		}
+	}
+	if this.Profiles != nil {
+		logIgnore("Profiles", this.Profiles, "invalid for profiles")
+	}
+	upgraded.Root = this.Root
+	if this.RuntimeOverlay != nil {
+		switch overlay := this.RuntimeOverlay.(type) {
+		case string:
+			upgraded.RuntimeOverlay = append(upgraded.RuntimeOverlay, strings.Split(overlay, ",")...)
+		case []interface{}:
+			for _, each := range overlay {
+				upgraded.RuntimeOverlay = append(upgraded.RuntimeOverlay, each.(string))
+			}
+		default:
+			wwlog.Error("unparsable RuntimeOverlay: %v", overlay)
+		}
+	}
+	if this.SystemOverlay != nil {
+		switch overlay := this.SystemOverlay.(type) {
+		case string:
+			upgraded.SystemOverlay = append(upgraded.SystemOverlay, strings.Split(overlay, ",")...)
+		case []interface{}:
+			for _, each := range overlay {
+				upgraded.SystemOverlay = append(upgraded.SystemOverlay, each.(string))
+			}
+		default:
+			wwlog.Error("unparsable SystemOverlay: %v", overlay)
+		}
+	}
+	if replaceOverlays {
+		if indexOf(upgraded.SystemOverlay, "wwinit") != -1 {
+			upgraded.SystemOverlay = replaceSliceElement(
+				upgraded.SystemOverlay,
+				indexOf(upgraded.SystemOverlay, "wwinit"),
+				wwinitSplitOverlays)
+		}
+		if indexOf(upgraded.RuntimeOverlay, "generic") != -1 {
+			upgraded.RuntimeOverlay = replaceSliceElement(
+				upgraded.RuntimeOverlay,
+				indexOf(upgraded.RuntimeOverlay, "generic"),
+				genericSplitOverlays)
+		}
+	}
+	if this.Tags != nil {
+		for key, value := range this.Tags {
+			upgraded.Tags[key] = value
+		}
+	}
+	for _, tag := range this.TagsDel {
+		delete(upgraded.Tags, tag)
+	}
+	return
+}
+
+type IpmiConf struct {
+	EscapeChar string            `yaml:"escapechar,omitempty"`
+	Gateway    string            `yaml:"gateway,omitempty"`
+	Interface  string            `yaml:"interface,omitempty"`
+	Ipaddr     string            `yaml:"ipaddr,omitempty"`
+	Netmask    string            `yaml:"netmask,omitempty"`
+	Password   string            `yaml:"password,omitempty"`
+	Port       string            `yaml:"port,omitempty"`
+	Tags       map[string]string `yaml:"tags,omitempty"`
+	TagsDel    []string          `yaml:"tagsdel,omitempty"`
+	UserName   string            `yaml:"username,omitempty"`
+	Write      string            `yaml:"write,omitempty"`
+}
+
+func (this *IpmiConf) Upgrade() (upgraded *node.IpmiConf) {
+	upgraded = new(node.IpmiConf)
+	upgraded.Tags = make(map[string]string)
+	upgraded.EscapeChar = this.EscapeChar
+	upgraded.Gateway = net.ParseIP(this.Gateway)
+	upgraded.Interface = this.Interface
+	upgraded.Ipaddr = net.ParseIP(this.Ipaddr)
+	upgraded.Netmask = net.ParseIP(this.Netmask)
+	upgraded.Password = this.Password
+	upgraded.Port = this.Port
+	if this.Tags != nil {
+		for key, value := range this.Tags {
+			upgraded.Tags[key] = value
+		}
+	}
+	for _, tag := range this.TagsDel {
+		delete(upgraded.Tags, tag)
+	}
+	upgraded.UserName = this.UserName
+	if this.Write != "" {
+		warnError(upgraded.Write.Set(this.Write))
+	}
+	return
+}
+
+type KernelConf struct {
+	Args     string `yaml:"args,omitempty"`
+	Override string `yaml:"override,omitempty"`
+	Version  string `yaml:"version,omitempty"`
+}
+
+func (this *KernelConf) Upgrade() (upgraded *node.KernelConf) {
+	upgraded = new(node.KernelConf)
+	upgraded.Args = this.Args
+	upgraded.Override = this.Override
+	upgraded.Version = this.Version
+	return
+}
+
+type NetDev struct {
+	Default string            `yaml:"default"`
+	Device  string            `yaml:"device,omitempty"`
+	Gateway string            `yaml:"gateway,omitempty"`
+	Hwaddr  string            `yaml:"hwaddr,omitempty"`
+	IpCIDR  string            `yaml:"ipcidr,omitempty"`
+	Ipaddr  string            `yaml:"ipaddr,omitempty"`
+	Ipaddr6 string            `yaml:"ip6addr,omitempty"`
+	MTU     string            `yaml:"mtu,omitempty"`
+	Netmask string            `yaml:"netmask,omitempty"`
+	OnBoot  string            `yaml:"onboot,omitempty"`
+	Prefix  string            `yaml:"prefix,omitempty"`
+	Primary string            `yaml:"primary,omitempty"`
+	Tags    map[string]string `yaml:"tags,omitempty"`
+	TagsDel []string          `yaml:"tagsdel,omitempty"`
+	Type    string            `yaml:"type,omitempty"`
+}
+
+func (this *NetDev) Upgrade(addDefaults bool) (upgraded *node.NetDev) {
+	upgraded = new(node.NetDev)
+	upgraded.Tags = make(map[string]string)
+	upgraded.Device = this.Device
+	upgraded.Gateway = net.ParseIP(this.Gateway)
+	upgraded.Hwaddr = this.Hwaddr
+	upgraded.Ipaddr = net.ParseIP(this.Ipaddr)
+	upgraded.Ipaddr6 = net.ParseIP(this.Ipaddr6)
+	upgraded.MTU = this.MTU
+	upgraded.Netmask = net.ParseIP(this.Netmask)
+	if this.IpCIDR != "" {
+		cidrIP, cidrIPNet, err := net.ParseCIDR(this.IpCIDR)
+		if err != nil {
+			wwlog.Error("%v is not a valid CIDR address: %w", this.IpCIDR, err)
+		} else {
+			if upgraded.Ipaddr == nil {
+				upgraded.Ipaddr = cidrIP
+			}
+			if upgraded.Netmask == nil {
+				upgraded.Netmask = net.IP(cidrIPNet.Mask)
+			}
+		}
+	}
+	if this.OnBoot != "" {
+		warnError(upgraded.OnBoot.Set(this.OnBoot))
+	}
+	upgraded.Prefix = net.ParseIP(this.Prefix)
+	if this.Tags != nil {
+		for key, value := range this.Tags {
+			upgraded.Tags[key] = value
+		}
+	}
+	for _, tag := range this.TagsDel {
+		delete(upgraded.Tags, tag)
+	}
+	upgraded.Type = this.Type
+	if addDefaults {
+		if upgraded.Type == "" {
+			upgraded.Type = "ethernet"
+		}
+		if upgraded.Netmask == nil {
+			upgraded.Netmask = net.ParseIP("255.255.255.0")
+		}
+	}
+	return
+}
+
+type Disk struct {
+	Partitions map[string]*Partition `yaml:"partitions,omitempty"`
+	WipeTable  string                `yaml:"wipe_table,omitempty"`
+}
+
+func (this *Disk) Upgrade() (upgraded *node.Disk) {
+	upgraded = new(node.Disk)
+	upgraded.Partitions = make(map[string]*node.Partition)
+	if this.Partitions != nil {
+		for name, partition := range this.Partitions {
+			upgraded.Partitions[name] = partition.Upgrade()
+		}
+	}
+	upgraded.WipeTable, _ = strconv.ParseBool(this.WipeTable)
+	return
+}
+
+type Partition struct {
+	Guid               string `yaml:"guid,omitempty"`
+	Number             string `yaml:"number,omitempty"`
+	Resize             string `yaml:"resize,omitempty"`
+	ShouldExist        string `yaml:"should_exist,omitempty"`
+	SizeMiB            string `yaml:"size_mib,omitempty"`
+	StartMiB           string `yaml:"start_mib,omitempty"`
+	TypeGuid           string `yaml:"type_guid,omitempty"`
+	WipePartitionEntry string `yaml:"wipe_partition_entry,omitempty"`
+}
+
+func (this *Partition) Upgrade() (upgraded *node.Partition) {
+	upgraded = new(node.Partition)
+	upgraded.Guid = this.Guid
+	upgraded.Number = this.Number
+	upgraded.Resize, _ = strconv.ParseBool(this.Resize)
+	upgraded.ShouldExist, _ = strconv.ParseBool(this.ShouldExist)
+	upgraded.SizeMiB = this.SizeMiB
+	upgraded.StartMiB = this.StartMiB
+	upgraded.TypeGuid = this.TypeGuid
+	upgraded.WipePartitionEntry, _ = strconv.ParseBool(this.WipePartitionEntry)
+	return
+}
+
+type FileSystem struct {
+	Format         string      `yaml:"format,omitempty"`
+	Label          string      `yaml:"label,omitempty"`
+	MountOptions   interface{} `yaml:"mount_options,omitempty"`
+	Options        []string    `yaml:"options,omitempty"`
+	Path           string      `yaml:"path,omitempty"`
+	Uuid           string      `yaml:"uuid,omitempty"`
+	WipeFileSystem string      `yaml:"wipe_filesystem,omitempty"`
+}
+
+func (this *FileSystem) Upgrade() (upgraded *node.FileSystem) {
+	upgraded = new(node.FileSystem)
+	upgraded.Options = make([]string, 0)
+	upgraded.Format = this.Format
+	upgraded.Label = this.Label
+	if this.MountOptions != nil {
+		switch mountOptions := this.MountOptions.(type) {
+		case string:
+			upgraded.MountOptions = mountOptions
+		case []interface{}:
+			mountOptionsStrings := make([]string, 0)
+			for _, option := range mountOptions {
+				mountOptionsStrings = append(mountOptionsStrings, option.(string))
+			}
+			upgraded.MountOptions = strings.Join(mountOptionsStrings, " ")
+		default:
+			wwlog.Error("unparsable MountOptions: %v", mountOptions)
+		}
+	}
+	upgraded.Options = append(upgraded.Options, this.Options...)
+	upgraded.Path = this.Path
+	upgraded.Uuid = this.Uuid
+	upgraded.WipeFileSystem, _ = strconv.ParseBool(this.WipeFileSystem)
+	return
+}
diff --git a/internal/pkg/upgrade/node_test.go b/internal/pkg/upgrade/node_test.go
new file mode 100644
index 00000000..1f28f563
--- /dev/null
+++ b/internal/pkg/upgrade/node_test.go
@@ -0,0 +1,700 @@
+package upgrade
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var nodesYamlUpgradeTests = []struct {
+	name            string
+	addDefaults     bool
+	replaceOverlays bool
+	legacyYaml      string
+	upgradedYaml    string
+}{
+	{
+		name:            "captured vers42 example",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodeprofiles:
+  default:
+    comment: This profile is automatically included for each node
+    runtime overlay: "generic"
+    discoverable: false
+  leap:
+    comment: openSUSE leap
+    kernel version: 5.14.21
+    ipmi netmask: "255.255.255.0"
+    keys:
+      foo: baar
+    network devices:
+      lan1:
+        gateway: 1.1.1.1
+nodes:
+  node01:
+    system overlay: "nodeoverlay"
+    discoverable: true
+    network devices:
+      eth0:
+        ipaddr: 1.2.3.4
+        default: true
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default:
+    comment: This profile is automatically included for each node
+    runtime overlay:
+      - generic
+  leap:
+    comment: openSUSE leap
+    kernel:
+      version: 5.14.21
+    ipmi:
+      netmask: 255.255.255.0
+    network devices:
+      lan1:
+        gateway: 1.1.1.1
+    tags:
+      foo: baar
+nodes:
+  node01:
+    discoverable: "true"
+    system overlay:
+      - nodeoverlay
+    network devices:
+      eth0:
+        ipaddr: 1.2.3.4
+    primary network: eth0
+`,
+	},
+	{
+		name:            "captured vers43 example",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+WW_INTERNAL: 45
+nodeprofiles:
+  default:
+    comment: This profile is automatically included for each node
+    runtime overlay:
+    - generic
+    discoverable: "false"
+  leap:
+    comment: openSUSE leap
+    kernel:
+      override: 5.14.21
+    ipmi:
+      netmask: 255.255.255.0
+    discoverable: "false"
+    network devices:
+      lan1:
+        device: lan1
+        gateway: 1.1.1.1
+        default: "false"
+    keys:
+      foo: baar
+nodes:
+  node01:
+    system overlay:
+    - nodeoverlay
+    discoverable: "true"
+    network devices:
+      eth0:
+        device: eth0
+        ipaddr: 1.2.3.4
+        default: "true"
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default:
+    comment: This profile is automatically included for each node
+    runtime overlay:
+      - generic
+  leap:
+    comment: openSUSE leap
+    kernel:
+      override: 5.14.21
+    ipmi:
+      netmask: 255.255.255.0
+    network devices:
+      lan1:
+        device: lan1
+        gateway: 1.1.1.1
+    tags:
+      foo: baar
+nodes:
+  node01:
+    discoverable: "true"
+    system overlay:
+      - nodeoverlay
+    network devices:
+      eth0:
+        device: eth0
+        ipaddr: 1.2.3.4
+    primary network: eth0
+`,
+	},
+	{
+		name:            "remove WW_INTERNAL",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml:      `WW_INTERNAL: 45`,
+		upgradedYaml: `
+nodeprofiles: {}
+nodes: {}
+`,
+	},
+	{
+		name:            "disabled is obsolete",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodes:
+  n1:
+    disabled: true
+nodeprofiles:
+  default:
+    disabled: true
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default: {}
+nodes:
+  n1: {}
+`,
+	},
+	{
+		name:            "inline IPMI settings",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodes:
+  n1:
+    ipmi escapechar: "~"
+    ipmi gateway: 192.168.0.1
+    ipmi interface: lanplus
+    ipmi ipaddr: 192.168.0.100
+    ipmi netmask: 255.255.255.0
+    ipmi password: password
+    ipmi port: 623
+    ipmi username: admin
+    ipmi write: true
+nodeprofiles:
+  default:
+    ipmi escapechar: "~"
+    ipmi gateway: 192.168.0.1
+    ipmi interface: lanplus
+    ipmi ipaddr: 192.168.0.100
+    ipmi netmask: 255.255.255.0
+    ipmi password: password
+    ipmi port: 623
+    ipmi username: admin
+    ipmi write: true
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default:
+    ipmi:
+      username: admin
+      password: password
+      ipaddr: 192.168.0.100
+      gateway: 192.168.0.1
+      netmask: 255.255.255.0
+      port: "623"
+      interface: lanplus
+      escapechar: "~"
+      write: "true"
+nodes:
+  n1:
+    ipmi:
+      username: admin
+      password: password
+      ipaddr: 192.168.0.100
+      gateway: 192.168.0.1
+      netmask: 255.255.255.0
+      port: "623"
+      interface: lanplus
+      escapechar: "~"
+      write: "true"
+`,
+	},
+	{
+		name:            "inline Kernel settings",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodeprofiles:
+  default:
+    kernel args: quiet
+    kernel override: rockylinux-9
+    kernel version: 2.6
+nodes:
+  n1:
+    kernel args: quiet
+    kernel override: rockylinux-9
+    kernel version: 2.6
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default:
+    kernel:
+      version: "2.6"
+      override: rockylinux-9
+      args: quiet
+nodes:
+  n1:
+    kernel:
+      version: "2.6"
+      override: rockylinux-9
+      args: quiet
+`,
+	},
+	{
+		name:            "keys and tags",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodeprofiles:
+  default:
+    keys:
+      key1: val1
+      key2: val2
+    tags:
+      key2: valB
+      key3: valC
+      key4: valD
+    tagsdel:
+      - key4
+    network devices:
+      default:
+        tags:
+          key2: valB
+          key3: valC
+          key4: valD
+        tagsdel:
+          - key4
+    ipmi:
+      tags:
+        key2: valB
+        key3: valC
+        key4: valD
+      tagsdel:
+        - key4
+nodes:
+  n1:
+    keys:
+      key1: val1
+      key2: val2
+    tags:
+      key2: valB
+      key3: valC
+      key4: valD
+    tagsdel:
+      - key4
+    network devices:
+      default:
+        tags:
+          key2: valB
+          key3: valC
+          key4: valD
+        tagsdel:
+          - key4
+    ipmi:
+      tags:
+        key2: valB
+        key3: valC
+        key4: valD
+      tagsdel:
+        - key4
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default:
+    ipmi:
+      tags:
+        key2: valB
+        key3: valC
+    network devices:
+      default:
+        tags:
+          key2: valB
+          key3: valC
+    tags:
+      key1: val1
+      key2: valB
+      key3: valC
+nodes:
+  n1:
+    ipmi:
+      tags:
+        key2: valB
+        key3: valC
+    network devices:
+      default:
+        tags:
+          key2: valB
+          key3: valC
+    tags:
+      key1: val1
+      key2: valB
+      key3: valC
+`,
+	},
+	{
+		name:            "primary network",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodes:
+  n1:
+    network devices:
+      eth0: {}
+      eth1:
+        default: true
+  n2:
+    network devices:
+      eth0:
+        primary: true
+      eth1: {}
+  n3:
+    network devices:
+      eth0:
+        primary: true
+      eth1: {}
+    primary network: eth1
+nodeprofiles:
+  p1:
+    network devices:
+      eth0: {}
+      eth1:
+        default: true
+  p2:
+    network devices:
+      eth0:
+        primary: true
+      eth1: {}
+  p3:
+    network devices:
+      eth0:
+        primary: true
+      eth1: {}
+    primary network: eth1
+`,
+		upgradedYaml: `
+nodeprofiles:
+  p1:
+    primary network: eth1
+  p2:
+    primary network: eth0
+  p3:
+    primary network: eth1
+nodes:
+  n1:
+    primary network: eth1
+  n2:
+    primary network: eth0
+  n3:
+    primary network: eth1
+`,
+	},
+	{
+		name:            "overlays",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodes:
+  n1:
+    runtime overlay:
+    - r1
+    - r2
+    system overlay:
+    - s1
+    - s2
+  n2:
+    runtime overlay: r1,r2
+    system overlay: s1,s2
+nodeprofiles:
+  p1:
+    runtime overlay:
+    - r1
+    - r2
+    system overlay:
+    - s1
+    - s2
+  p2:
+    runtime overlay: r1,r2
+    system overlay: s1,s2
+`,
+		upgradedYaml: `
+nodeprofiles:
+  p1:
+    runtime overlay:
+      - r1
+      - r2
+    system overlay:
+      - s1
+      - s2
+  p2:
+    runtime overlay:
+      - r1
+      - r2
+    system overlay:
+      - s1
+      - s2
+nodes:
+  n1:
+    runtime overlay:
+      - r1
+      - r2
+    system overlay:
+      - s1
+      - s2
+  n2:
+    runtime overlay:
+      - r1
+      - r2
+    system overlay:
+      - s1
+      - s2
+`,
+	},
+	{
+		name:            "disk example",
+		addDefaults:     false,
+		replaceOverlays: false,
+		legacyYaml: `
+nodes:
+  n1:
+    disks:
+      /dev/vda:
+        wipe_table: true
+        partitions:
+          scratch:
+            number: "1"
+            should_exist: true
+          swap:
+            number: "2"
+            size_mib: "1024"
+    filesystems:
+      /dev/disk/by-partlabel/scratch:
+        format: btrfs
+        path: /scratch
+      /dev/disk/by-partlabel/swap:
+        format: swap
+        path: swap
+`,
+		upgradedYaml: `
+nodeprofiles: {}
+nodes:
+  n1:
+    disks:
+      /dev/vda:
+        wipe_table: true
+        partitions:
+          scratch:
+            number: "1"
+            should_exist: true
+          swap:
+            number: "2"
+            size_mib: "1024"
+    filesystems:
+      /dev/disk/by-partlabel/scratch:
+        format: btrfs
+        path: /scratch
+      /dev/disk/by-partlabel/swap:
+        format: swap
+        path: swap
+`,
+	},
+	{
+		name:            "add defaults",
+		addDefaults:     true,
+		replaceOverlays: false,
+		legacyYaml: `
+nodes:
+  n1:
+    network devices:
+      default:
+        ipaddr: 192.168.0.100
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default:
+    ipxe template: default
+    runtime overlay:
+      - hosts
+      - ssh.authorized_keys
+      - syncuser
+    system overlay:
+      - wwinit
+      - wwclient
+      - fstab
+      - hostname
+      - ssh.host_keys
+      - issue
+      - resolv
+      - udev.netname
+      - systemd.netname
+      - ifcfg
+      - NetworkManager
+      - debian.interfaces
+      - wicked
+      - ignition
+    kernel:
+      args: quiet crashkernel=no vga=791 net.naming-scheme=v238
+    init: /sbin/init
+    root: initramfs
+nodes:
+  n1:
+    profiles:
+      - default
+    network devices:
+      default:
+        type: ethernet
+        ipaddr: 192.168.0.100
+        netmask: 255.255.255.0
+`,
+	},
+	{
+		name:            "add defaults conflicts",
+		addDefaults:     true,
+		replaceOverlays: false,
+		legacyYaml: `
+nodeprofiles:
+  default:
+    system overlay:
+      - wwinit
+      - wwclient
+      - fstab
+      - hostname
+      - ssh.host_keys
+      - issue
+      - resolv
+      - udev.netname
+      - systemd.netname
+      - NetworkManager
+  custom: {}
+nodes:
+  n1:
+    profiles:
+      - custom
+    network devices:
+      default:
+        ipaddr: 10.0.0.100
+        netmask: 255.255.0.0
+`,
+		upgradedYaml: `
+nodeprofiles:
+  custom: {}
+  default:
+    ipxe template: default
+    runtime overlay:
+      - hosts
+      - ssh.authorized_keys
+      - syncuser
+    system overlay:
+      - wwinit
+      - wwclient
+      - fstab
+      - hostname
+      - ssh.host_keys
+      - issue
+      - resolv
+      - udev.netname
+      - systemd.netname
+      - NetworkManager
+    kernel:
+      args: quiet crashkernel=no vga=791 net.naming-scheme=v238
+    init: /sbin/init
+    root: initramfs
+nodes:
+  n1:
+    profiles:
+      - custom
+    network devices:
+      default:
+        type: ethernet
+        ipaddr: 10.0.0.100
+        netmask: 255.255.0.0
+`,
+	},
+	{
+		name:            "add defaults conflicts",
+		addDefaults:     false,
+		replaceOverlays: true,
+		legacyYaml: `
+nodeprofiles:
+  default:
+    runtime overlay:
+      - generic
+    system overlay:
+      - wwinit
+nodes:
+  n1:
+    runtime overlay:
+      - generic
+    system overlay:
+      - wwinit
+`,
+		upgradedYaml: `
+nodeprofiles:
+  default:
+    runtime overlay:
+      - hosts
+      - ssh.authorized_keys
+      - syncuser
+    system overlay:
+      - wwinit
+      - wwclient
+      - fstab
+      - hostname
+      - ssh.host_keys
+      - issue
+      - resolv
+      - udev.netname
+      - systemd.netname
+      - ifcfg
+      - NetworkManager
+      - debian.interfaces
+      - wicked
+      - ignition
+nodes:
+  n1:
+    runtime overlay:
+      - hosts
+      - ssh.authorized_keys
+      - syncuser
+    system overlay:
+      - wwinit
+      - wwclient
+      - fstab
+      - hostname
+      - ssh.host_keys
+      - issue
+      - resolv
+      - udev.netname
+      - systemd.netname
+      - ifcfg
+      - NetworkManager
+      - debian.interfaces
+      - wicked
+      - ignition
+`,
+	},
+}
+
+func Test_UpgradeNodesYaml(t *testing.T) {
+	for _, tt := range nodesYamlUpgradeTests {
+		t.Run(tt.name, func(t *testing.T) {
+			legacy, err := ParseNodes([]byte(tt.legacyYaml))
+			assert.NoError(t, err)
+			upgraded := legacy.Upgrade(tt.addDefaults, tt.replaceOverlays)
+			upgradedYaml, err := upgraded.Dump()
+			assert.NoError(t, err)
+			assert.Equal(t, strings.TrimSpace(tt.upgradedYaml), strings.TrimSpace(string(upgradedYaml)))
+		})
+	}
+}
diff --git a/internal/pkg/upgrade/slices.go b/internal/pkg/upgrade/slices.go
new file mode 100644
index 00000000..780350d3
--- /dev/null
+++ b/internal/pkg/upgrade/slices.go
@@ -0,0 +1,17 @@
+package upgrade
+
+func indexOf[T comparable](slice []T, item T) int {
+	for i, v := range slice {
+		if v == item {
+			return i
+		}
+	}
+	return -1
+}
+
+func replaceSliceElement[T any](original []T, index int, replacement []T) []T {
+	if index < 0 || index >= len(original) {
+		return original
+	}
+	return append(original[:index], append(replacement, original[index+1:]...)...)
+}
diff --git a/internal/pkg/util/util.go b/internal/pkg/util/util.go
index 67b95378..e2099844 100644
--- a/internal/pkg/util/util.go
+++ b/internal/pkg/util/util.go
@@ -18,6 +18,10 @@ import (
 	"github.com/warewulf/warewulf/internal/pkg/wwlog"
 )
 
+func BoolP(p *bool) bool {
+	return p != nil && *p
+}
+
 func FirstError(errs ...error) (err error) {
 	for _, e := range errs {
 		if err == nil {
diff --git a/internal/pkg/warewulfd/daemon.go b/internal/pkg/warewulfd/daemon.go
index 2ab8f6ba..1a338f71 100644
--- a/internal/pkg/warewulfd/daemon.go
+++ b/internal/pkg/warewulfd/daemon.go
@@ -57,7 +57,7 @@ func DaemonInitLogging() error {
 
 	conf := warewulfconf.Get()
 
-	if conf.Warewulf.Syslog {
+	if conf.Warewulf.Syslog() {
 
 		wwlog.Debug("Changing log output to syslog")
 
diff --git a/internal/pkg/warewulfd/nodedb.go b/internal/pkg/warewulfd/nodedb.go
index 32903c4a..e9f23986 100644
--- a/internal/pkg/warewulfd/nodedb.go
+++ b/internal/pkg/warewulfd/nodedb.go
@@ -12,7 +12,7 @@ import (
 type nodeDB struct {
 	lock     sync.RWMutex
 	NodeInfo map[string]string
-	yml      node.NodeYaml
+	yml      node.NodesYaml
 }
 
 var (
@@ -53,7 +53,7 @@ func loadNodeDB() (err error) {
 	return nil
 }
 
-func GetNodeOrSetDiscoverable(hwaddr string) (node.NodeConf, error) {
+func GetNodeOrSetDiscoverable(hwaddr string) (node.Node, error) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 	// NOTE: since discoverable nodes will write an updated DB to file and then
diff --git a/internal/pkg/warewulfd/provision.go b/internal/pkg/warewulfd/provision.go
index 9426e067..5a165a55 100644
--- a/internal/pkg/warewulfd/provision.go
+++ b/internal/pkg/warewulfd/provision.go
@@ -35,7 +35,7 @@ type templateVars struct {
 	KernelArgs     string
 	KernelOverride string
 	Tags           map[string]string
-	NetDevs        map[string]*node.NetDevs
+	NetDevs        map[string]*node.NetDev
 }
 
 func ProvisionSend(w http.ResponseWriter, req *http.Request) {
@@ -50,7 +50,7 @@ func ProvisionSend(w http.ResponseWriter, req *http.Request) {
 
 	wwlog.Info("request from hwaddr:%s ipaddr:%s | stage:%s", rinfo.hwaddr, req.RemoteAddr, rinfo.stage)
 
-	if (rinfo.stage == "runtime" || len(rinfo.overlay) > 0) && conf.Warewulf.Secure {
+	if (rinfo.stage == "runtime" || len(rinfo.overlay) > 0) && conf.Warewulf.Secure() {
 		if rinfo.remoteport >= 1024 {
 			wwlog.Denied("Non-privileged port: %s", req.RemoteAddr)
 			w.WriteHeader(http.StatusUnauthorized)
@@ -149,7 +149,7 @@ func ProvisionSend(w http.ResponseWriter, req *http.Request) {
 			remoteNode,
 			context,
 			request_overlays,
-			conf.Warewulf.AutobuildOverlays)
+			conf.Warewulf.AutobuildOverlays())
 
 		if err != nil {
 			if errors.Is(err, overlay.ErrDoesNotExist) {
diff --git a/internal/pkg/warewulfd/provision_test.go b/internal/pkg/warewulfd/provision_test.go
index ba1bc977..cc35f909 100644
--- a/internal/pkg/warewulfd/provision_test.go
+++ b/internal/pkg/warewulfd/provision_test.go
@@ -37,8 +37,7 @@ var provisionSendTests = []struct {
 func Test_ProvisionSend(t *testing.T) {
 	env := testenv.New(t)
 
-	env.WriteFile(t, "etc/warewulf/nodes.conf", `WW_INTERNAL: 45
-nodeprofiles:
+	env.WriteFile(t, "etc/warewulf/nodes.conf", `nodeprofiles:
   default:
     container name: suse
 nodes:
@@ -102,7 +101,8 @@ nodes:
 	dbErr := LoadNodeDB()
 	assert.NoError(t, dbErr)
 
-	conf.Warewulf.Secure = false
+	secureFalse := false
+	conf.Warewulf.SecureP = &secureFalse
 	assert.NoError(t, os.MkdirAll(path.Join(conf.Paths.OverlayProvisiondir(), "n1"), 0700))
 	assert.NoError(t, os.WriteFile(path.Join(conf.Paths.OverlayProvisiondir(), "n1", "__SYSTEM__.img"), []byte("system overlay"), 0600))
 	assert.NoError(t, os.WriteFile(path.Join(conf.Paths.OverlayProvisiondir(), "n1", "__RUNTIME__.img"), []byte("runtime overlay"), 0600))
diff --git a/internal/pkg/warewulfd/util.go b/internal/pkg/warewulfd/util.go
index 0ba04921..7938d343 100644
--- a/internal/pkg/warewulfd/util.go
+++ b/internal/pkg/warewulfd/util.go
@@ -44,7 +44,7 @@ func sendFile(
 	return nil
 }
 
-func getOverlayFile(n node.NodeConf, context string, stage_overlays []string, autobuild bool) (stage_file string, err error) {
+func getOverlayFile(n node.Node, context string, stage_overlays []string, autobuild bool) (stage_file string, err error) {
 
 	stage_file = overlay.OverlayImage(n.Id(), context, stage_overlays)
 	err = nil
@@ -60,9 +60,9 @@ func getOverlayFile(n node.NodeConf, context string, stage_overlays []string, au
 
 	if build {
 		if len(stage_overlays) > 0 {
-			err = overlay.BuildSpecificOverlays([]node.NodeConf{n}, stage_overlays)
+			err = overlay.BuildSpecificOverlays([]node.Node{n}, stage_overlays)
 		} else {
-			err = overlay.BuildAllOverlays([]node.NodeConf{n})
+			err = overlay.BuildAllOverlays([]node.Node{n})
 		}
 		if err != nil {
 			wwlog.Error("Failed to build overlay: %s, %s, %s\n%s",
diff --git a/overlays/NetworkManager/internal/nodes.conf b/overlays/NetworkManager/internal/nodes.conf
index fefbdbc8..33a7b4d2 100644
--- a/overlays/NetworkManager/internal/nodes.conf
+++ b/overlays/NetworkManager/internal/nodes.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 45
 nodes:
   node1:
     network devices:
diff --git a/overlays/NetworkManager/internal/nodes.conf-vlan b/overlays/NetworkManager/internal/nodes.conf-vlan
index 3302207f..71338a9a 100644
--- a/overlays/NetworkManager/internal/nodes.conf-vlan
+++ b/overlays/NetworkManager/internal/nodes.conf-vlan
@@ -3,8 +3,10 @@ nodes:
     primary network: untagged
     network devices:
       untagged:
+        onboot: true
         device: eth0
       tagged:
+        onboot: true
         type: vlan
         device: eth0.902
         tags:
diff --git a/overlays/NetworkManager/internal/nodes_empty_mac.conf b/overlays/NetworkManager/internal/nodes_empty_mac.conf
index 7f95f690..b1aa5217 100644
--- a/overlays/NetworkManager/internal/nodes_empty_mac.conf
+++ b/overlays/NetworkManager/internal/nodes_empty_mac.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 45
 nodes:
   node1:
     network devices:
diff --git a/overlays/NetworkManager/rootfs/etc/NetworkManager/system-connections/ww4-managed.ww b/overlays/NetworkManager/rootfs/etc/NetworkManager/system-connections/ww4-managed.ww
index 2640b892..1c0e5c7c 100644
--- a/overlays/NetworkManager/rootfs/etc/NetworkManager/system-connections/ww4-managed.ww
+++ b/overlays/NetworkManager/rootfs/etc/NetworkManager/system-connections/ww4-managed.ww
@@ -14,7 +14,7 @@ master={{ $master }}
 type=ethernet
 {{- else }}
 type={{if $netdev.Type}}{{ $netdev.Type }}{{ else }}ethernet{{end}}
-{{- if or $netdev.OnBoot (eq $netdev.OnBoot nil) }}
+{{- if $netdev.OnBoot }}
 autoconnect=true
 {{- end }}
 {{- end }}
diff --git a/overlays/debian.interfaces/internal/debian_interfaces_test.go b/overlays/debian.interfaces/internal/debian_interfaces_test.go
index ad0a3ade..2b2e5f97 100644
--- a/overlays/debian.interfaces/internal/debian_interfaces_test.go
+++ b/overlays/debian.interfaces/internal/debian_interfaces_test.go
@@ -53,7 +53,6 @@ const debian_interfaces string = `backupFile: true
 writeFile: true
 Filename: default
 # This file is autogenerated by warewulf
-auto wwnet0
 allow-hotplug wwnet0
 iface wwnet0 inet static
   address 192.168.3.21
@@ -64,7 +63,6 @@ backupFile: true
 writeFile: true
 Filename: secondary
 # This file is autogenerated by warewulf
-auto wwnet1
 allow-hotplug wwnet1
 iface wwnet1 inet static
   address 192.168.3.22
diff --git a/overlays/debian.interfaces/rootfs/etc/network/interfaces.d/default.ww b/overlays/debian.interfaces/rootfs/etc/network/interfaces.d/default.ww
index 178ec263..e1fe1cdb 100644
--- a/overlays/debian.interfaces/rootfs/etc/network/interfaces.d/default.ww
+++ b/overlays/debian.interfaces/rootfs/etc/network/interfaces.d/default.ww
@@ -1,7 +1,7 @@
 {{- range $devname, $netdev := .ThisNode.NetDevs }}
 {{- file $devname }}
 # This file is autogenerated by warewulf
-{{- if or $netdev.OnBoot (eq $netdev.OnBoot nil) }}
+{{- if $netdev.OnBoot }}
 auto {{ $netdev.Device }}
 {{- end }}
 allow-hotplug {{ $netdev.Device }}
diff --git a/overlays/fstab/internal/warewulf.conf b/overlays/fstab/internal/warewulf.conf
index 56d81ac5..7c5f020c 100644
--- a/overlays/fstab/internal/warewulf.conf
+++ b/overlays/fstab/internal/warewulf.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 43
 ipaddr: 192.168.0.1/24
 netmask: 255.255.255.0
 network: 192.168.0.0
diff --git a/overlays/host/internal/warewulf.conf b/overlays/host/internal/warewulf.conf
index 56d81ac5..7c5f020c 100644
--- a/overlays/host/internal/warewulf.conf
+++ b/overlays/host/internal/warewulf.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 43
 ipaddr: 192.168.0.1/24
 netmask: 255.255.255.0
 network: 192.168.0.0
diff --git a/overlays/host/internal/warewulf.conf-static b/overlays/host/internal/warewulf.conf-static
index 4e3207c5..cd4b744d 100644
--- a/overlays/host/internal/warewulf.conf-static
+++ b/overlays/host/internal/warewulf.conf-static
@@ -1,4 +1,3 @@
-WW_INTERNAL: 43
 ipaddr: 192.168.0.1/24
 netmask: 255.255.255.0
 network: 192.168.0.0
diff --git a/overlays/hosts/internal/warewulf.conf b/overlays/hosts/internal/warewulf.conf
index 56d81ac5..7c5f020c 100644
--- a/overlays/hosts/internal/warewulf.conf
+++ b/overlays/hosts/internal/warewulf.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 43
 ipaddr: 192.168.0.1/24
 netmask: 255.255.255.0
 network: 192.168.0.0
diff --git a/overlays/ifcfg/internal/ifcfg_test.go b/overlays/ifcfg/internal/ifcfg_test.go
index 3725f4b6..c78b73f3 100644
--- a/overlays/ifcfg/internal/ifcfg_test.go
+++ b/overlays/ifcfg/internal/ifcfg_test.go
@@ -83,7 +83,6 @@ IPADDR=192.168.3.21
 NETMASK=255.255.255.0
 GATEWAY=192.168.3.1
 HWADDR=e6:92:39:49:7b:03
-ONBOOT=true
 IPV6INIT=yes
 IPV6_AUTOCONF=yes
 IPV6_DEFROUTE=yes
@@ -102,7 +101,6 @@ IPADDR=192.168.3.22
 NETMASK=255.255.255.0
 GATEWAY=192.168.3.1
 HWADDR=9a:77:29:73:14:f1
-ONBOOT=true
 IPV6INIT=yes
 IPV6_AUTOCONF=yes
 IPV6_DEFROUTE=yes
diff --git a/overlays/ifcfg/internal/nodes.conf-vlan b/overlays/ifcfg/internal/nodes.conf-vlan
index 1f418c08..1345481e 100644
--- a/overlays/ifcfg/internal/nodes.conf-vlan
+++ b/overlays/ifcfg/internal/nodes.conf-vlan
@@ -3,8 +3,10 @@ nodes:
     primary network: untagged
     network devices:
       untagged:
+        onboot: true
         device: eth0
       tagged:
+        onboot: true
         type: vlan
         device: eth0.902
         tags:
diff --git a/overlays/ifcfg/rootfs/etc/sysconfig/network-scripts/ifcfg.ww b/overlays/ifcfg/rootfs/etc/sysconfig/network-scripts/ifcfg.ww
index ffe040d5..f89b7c36 100644
--- a/overlays/ifcfg/rootfs/etc/sysconfig/network-scripts/ifcfg.ww
+++ b/overlays/ifcfg/rootfs/etc/sysconfig/network-scripts/ifcfg.ww
@@ -27,7 +27,7 @@ GATEWAY={{ $netdev.Gateway }}
 {{- if $netdev.Hwaddr }}
 HWADDR={{ $netdev.Hwaddr }}
 {{- end }}
-{{ if or $netdev.OnBoot (eq $netdev.OnBoot nil) -}}
+{{- if $netdev.OnBoot }}
 ONBOOT=true
 {{- end }}
 IPV6INIT=yes
diff --git a/overlays/wicked/internal/nodes.conf-vlan b/overlays/wicked/internal/nodes.conf-vlan
index 3302207f..71338a9a 100644
--- a/overlays/wicked/internal/nodes.conf-vlan
+++ b/overlays/wicked/internal/nodes.conf-vlan
@@ -3,8 +3,10 @@ nodes:
     primary network: untagged
     network devices:
       untagged:
+        onboot: true
         device: eth0
       tagged:
+        onboot: true
         type: vlan
         device: eth0.902
         tags:
diff --git a/overlays/wicked/internal/wicked_test.go b/overlays/wicked/internal/wicked_test.go
index 7b835d07..ffa7c32b 100644
--- a/overlays/wicked/internal/wicked_test.go
+++ b/overlays/wicked/internal/wicked_test.go
@@ -65,7 +65,7 @@ This file is autogenerated by warewulf
   <name>wwnet0</name>
   <link-type>ethernet</link-type>
   <control>
-    <mode>boot</mode>
+    <mode>manual</mode>
   </control>
   <firewall/>
   <link/>
@@ -99,7 +99,7 @@ This file is autogenerated by warewulf
   <name>wwnet1</name>
   <link-type>ethernet</link-type>
   <control>
-    <mode>boot</mode>
+    <mode>manual</mode>
   </control>
   <firewall/>
   <link/>
diff --git a/overlays/wicked/rootfs/etc/wicked/ifconfig/ifcfg.xml.ww b/overlays/wicked/rootfs/etc/wicked/ifconfig/ifcfg.xml.ww
index 19012c0d..4fd01a6a 100644
--- a/overlays/wicked/rootfs/etc/wicked/ifconfig/ifcfg.xml.ww
+++ b/overlays/wicked/rootfs/etc/wicked/ifconfig/ifcfg.xml.ww
@@ -18,7 +18,7 @@ This file is autogenerated by warewulf
   <mtu>{{ $netdev.MTU }}</mtu>
   {{- end }}
   <control>
-    <mode>{{ if or $netdev.OnBoot (eq $netdev.OnBoot nil) }}boot{{ else }}manual{{end}}</mode>
+    <mode>{{ if $netdev.OnBoot }}boot{{ else }}manual{{ end }}</mode>
   </control>
   <firewall/>
   <link/>
diff --git a/overlays/wwinit/internal/warewulf.conf b/overlays/wwinit/internal/warewulf.conf
index 56d81ac5..7c5f020c 100644
--- a/overlays/wwinit/internal/warewulf.conf
+++ b/overlays/wwinit/internal/warewulf.conf
@@ -1,4 +1,3 @@
-WW_INTERNAL: 43
 ipaddr: 192.168.0.1/24
 netmask: 255.255.255.0
 network: 192.168.0.0
diff --git a/overlays/wwinit/internal/wwinit_test.go b/overlays/wwinit/internal/wwinit_test.go
index 0ef11229..cb51a407 100644
--- a/overlays/wwinit/internal/wwinit_test.go
+++ b/overlays/wwinit/internal/wwinit_test.go
@@ -57,7 +57,6 @@ func Test_wwinitOverlay(t *testing.T) {
 const wwinit_warewulf_conf string = `backupFile: true
 writeFile: true
 Filename: etc/warewulf/warewulf.conf
-WW_INTERNAL: 43
 ipaddr: 192.168.0.1/24
 netmask: 255.255.255.0
 network: 192.168.0.0
diff --git a/userdocs/contents/configuration.rst b/userdocs/contents/configuration.rst
index b46443f6..13309244 100644
--- a/userdocs/contents/configuration.rst
+++ b/userdocs/contents/configuration.rst
@@ -14,7 +14,6 @@ Warewulf (4.5.2):
 
 .. code-block:: yaml
 
-   WW_INTERNAL: 45
    ipaddr: 10.0.0.1
    netmask: 255.255.252.0
    network: 10.0.0.0
@@ -202,6 +201,26 @@ command.
    This also goes for ``warewulf.conf`` as well - any changes made also require ``warewulfd`` to be restarted.
    The restart should be done using the following command: ``systemctl restart warewulfd``
 
+Upgrades
+========
+
+New versions of Warewulf might introduce changes to ``warewulf.conf`` and ``nodes.conf``.
+The ``wwctl upgrade`` command can help ease the transition between versions.
+
+.. note::
+
+   ``wwctl upgrade`` will back up any files before it changes them (to ``<name>-old``)
+   but it is good practice to back up your configuration manually.
+
+.. code-block:: console
+
+   # wwctl upgrade config
+   # wwctl upgrade nodes --add-defaults --replace-overlays
+
+Both upgrade commands support specifying ``--output-path=-``
+to print the upgraded configuration file to standard out
+for inspection before replacing the configuration files.
+
 Directories
 ===========
 
diff --git a/userdocs/contributing/development-environment-vagrant.rst b/userdocs/contributing/development-environment-vagrant.rst
index 8d8944b7..cbfab328 100644
--- a/userdocs/contributing/development-environment-vagrant.rst
+++ b/userdocs/contributing/development-environment-vagrant.rst
@@ -190,7 +190,6 @@ Vagrantfile
 
             head.vm.provision "shell", inline: <<-SHELL
                 cat << 'CONF' | sudo tee /etc/warewulf/warewulf.conf
-    WW_INTERNAL: 45
     ipaddr: 192.168.200.254
     netmask: 255.255.255.0
     network: 192.168.200.0
diff --git a/userdocs/quickstart/debian12.rst b/userdocs/quickstart/debian12.rst
index eaf4a9b8..f2692fa4 100644
--- a/userdocs/quickstart/debian12.rst
+++ b/userdocs/quickstart/debian12.rst
@@ -65,7 +65,6 @@ address of your cluster's private network interface:
 
 .. code-block:: yaml
 
-	WW_INTERNAL: 45
 	ipaddr: 192.168.200.1
 	netmask: 255.255.255.0
 	network: 192.168.200.0
diff --git a/userdocs/quickstart/el.rst b/userdocs/quickstart/el.rst
index 3edc50e7..e41de7b8 100644
--- a/userdocs/quickstart/el.rst
+++ b/userdocs/quickstart/el.rst
@@ -58,7 +58,6 @@ address of your cluster's private network interface.
 
 .. code-block:: yaml
 
-   WW_INTERNAL: 45
    ipaddr: 10.0.0.1
    netmask: 255.255.252.0
    network: 10.0.0.0
diff --git a/userdocs/quickstart/suse15.rst b/userdocs/quickstart/suse15.rst
index a6039c7f..355f36c7 100644
--- a/userdocs/quickstart/suse15.rst
+++ b/userdocs/quickstart/suse15.rst
@@ -46,7 +46,6 @@ address of your cluster's private network interface:
 
 .. code-block:: yaml
 
-    WW_INTERNAL: 45
     ipaddr: 192.168.200.1
     netmask: 255.255.255.0
     network: 192.168.200.0