When migrating a VM from one openshift cluster to another (same latest versions) the VirtualMachineCreation step fails with 

"admission webhook "virtualmachine-validator.kubevirt.io" denied the request: spec.template.spec.domain.devices.disks[1].Name 'cloudinitdisk' not found."

Source vm yaml definition is using cloud init
~~~
  devices:
    disks:
      - disk:
          bus: virtio
        name: rootdisk
      - disk:
          bus: virtio
        name: cloudinitdisk
    interfaces:
      - macAddress: 02:90:f6:00:00:00
        masquerade: {}
        model: virtio
        name: default
volumes:
  - dataVolume:
      name: fedora-fuchsia-hare-67
    name: rootdisk
  - cloudInitNoCloud:
      userData: |-
        #cloud-config
        user: fedora
        password: ujux-x6ax-jas3
        chpasswd: { expire: False }
    name: cloudinitdisk
~~~It would appear the vm yaml on the destination side may not be correctly getting applied as you can recreate this error when there is a mismatch between the disks.disk.name and what we see in volumes:

Source and destination clusters are configured with latest versions:
OCP 4.18.26
CNV 4.18.17
MTV 2.9.5 

Always

1. Create two OCP clusters running 4.18.X
2. Create a VM that uses cloudInitNoCloud 
3. Attempt to migrate VM

"admission webhook "virtualmachine-validator.kubevirt.io" denied the request: spec.template.spec.domain.devices.disks[1].Name 'cloudinitdisk' not found."

VM is created and starts up without issue. 

You can work around this by detatching the cloudinit disk on the source vm, but you then have to re-add it back after migration which is not ideal. 

I can confirm the vmexport which gets created on the source cluster contains the correct manifest 

oc logs  forklift-controller-7f4c746865-kqb6x 
{"level":"info","ts":"2025-10-14 15:11:04.978","logger":"plan|766cx","msg":"Found vm in manifest","plan":{"name":"test","namespace":"shaggy"},"migration":"shaggy/test-qdckx","vm":{"kind":"VirtualMachine","apiVersion":"kubevirt.io/v1","metadata":{"name":"fedora-fuchsia-hare-67","namespace":"default","creationTimestamp":null,"labels":{"app":"fedora-fuchsia-hare-67","kubevirt.io/dynamic-credentials-support":"true","vm.kubevirt.io/template":"fedora-server-small","vm.kubevirt.io/template.namespace":"openshift","vm.kubevirt.io/template.revision":"1","vm.kubevirt.io/template.version":"v0.32.2"},"annotations":{"kubemacpool.io/transaction-timestamp":"2025-10-14T15:09:08.519933018Z","kubevirt.io/latest-observed-api-version":"v1","kubevirt.io/storage-observed-api-version":"v1","vm.kubevirt.io/validations":"[\n  {\n    \"name\": \"minimal-required-memory\",\n    \"path\": \"jsonpath::.spec.domain.memory.guest\",\n    \"rule\": \"integer\",\n    \"message\": \"This VM requires more memory.\",\n    \"min\": 2147483648\n  }\n]\n"}},"spec":{"runStrategy":"Halted","template":{"metadata":{"creationTimestamp":null,"labels":{"kubevirt.io/domain":"fedora-fuchsia-hare-67","kubevirt.io/size":"small","network.kubevirt.io/headlessService":"headless"},"annotations":{"vm.kubevirt.io/flavor":"small","vm.kubevirt.io/os":"fedora","vm.kubevirt.io/workload":"server"}},"spec":{"domain":{"resources":{},"cpu":{"cores":1,"sockets":1,"threads":1},"memory":{"guest":"2Gi"},"machine":{"type":"pc-q35-rhel9.4.0"},"firmware":{"bootloader":{"efi":{}}},"features":{"acpi":{},"smm":{"enabled":true}},"devices":{"disks":[{"name":"rootdisk","disk":{"bus":"virtio"}},{"name":"cloudinitdisk","disk":{"bus":"virtio"}}],"interfaces":[{"name":"default","model":"virtio","masquerade":{},"macAddress":"02:90:f6:00:00:00"}],"rng":{}}},"terminationGracePeriodSeconds":180,"volumes":[{"name":"rootdisk","dataVolume":{"name":"fedora-fuchsia-hare-67"}},{"name":"cloudinitdisk","cloudInitNoCloud":{"userData":"#cloud-config\nuser: fedora\npassword: ujux-x6ax-jas3\nchpasswd: { expire: False }"}}],"networks":[{"name":"default","pod":{}}],"architecture":"amd64"}},"dataVolumeTemplates":[{"kind":"DataVolume","apiVersion":"cdi.kubevirt.io/v1beta1","metadata":{"name":"fedora-fuchsia-hare-67","creationTimestamp":null,"annotations":{"cdi.kubevirt.io/storage.bind.immediate.requested":"true"}},"spec":{"source":{"http":{"url":"https://virt-exportproxy-openshift-cnv.apps.ci-ln-82sy5n2-72292.origin-ci-int-gce.dev.rhcloud.com/api/export.kubevirt.io/v1beta1/namespaces/default/virtualmachineexports/fedora-fuchsia-hare-67/volumes/fedora-fuchsia-hare-67/disk.img.gz","certConfigMap":"export-ca-cm-fedora-fuchsia-hare-67","secretExtraHeaders":["header-secret-fedora-fuchsia-hare-67"]}},"storage":{"resources":{"requests":{"storage":"1Gi"}}}}}]},"status":{}}}