Missing vhd after a possibly failed migration

[goreandor]

Hi,

Was migrating one of our important VMs from a problematic pool to a new "clean" one. However, it failed half way through. I believe this is the correct log entry:

vm.migrate
{
  "vm": "b60762de-c222-2911-e18b-488c56e21646",
  "mapVifsNetworks": {
    "bc94ab3c-20ed-b188-5010-a4a9ea7c9196": "c0bd86ce-faaa-4fd9-a702-c093c3f5c326"
  },
  "migrationNetwork": "c0bd86ce-faaa-4fd9-a702-c093c3f5c326",
  "sr": "cb379d8c-0226-49aa-327f-00d12f63f43e",
  "targetHost": "cebfed0d-8a78-4d69-8817-2b9a4c81c59b"
}
{
  "code": 21,
  "data": {
    "objectId": "b60762de-c222-2911-e18b-488c56e21646",
    "code": "MIRROR_FAILED"
  },
  "message": "operation failed",
  "name": "XoError",
  "stack": "XoError: operation failed
    at operationFailed (/usr/local/lib/node_modules/xo-server/node_modules/xo-common/src/api-errors.js:21:32)
    at file:///usr/local/lib/node_modules/xo-server/src/api/vm.mjs:561:15
    at Xo.migrate (file:///usr/local/lib/node_modules/xo-server/src/api/vm.mjs:547:3)
    at Api.#callApiMethod (file:///usr/local/lib/node_modules/xo-server/src/xo-mixins/api.mjs:401:20)"
}

After that, VM locked up and I restarted it, but it failed to boot with the error below:

vm.start
{
  "id": "b60762de-c222-2911-e18b-488c56e21646",
  "bypassMacAddressesCheck": false,
  "force": false
}
{
  "code": "SR_BACKEND_FAILURE_46",
  "params": [
    "",
    "The VDI is not available [opterr=VDI 28aaf3f0-447c-44a2-ad8e-e7c159b41ef8 not detached cleanly]",
    ""
  ],
  "call": {
    "method": "VM.start",
    "params": [
      "OpaqueRef:aee5c672-049e-4533-81a2-7ac0163d818c",
      false,
      false
    ]
  },
  "message": "SR_BACKEND_FAILURE_46(, The VDI is not available [opterr=VDI 28aaf3f0-447c-44a2-ad8e-e7c159b41ef8 not detached cleanly], )",
  "name": "XapiError",
  "stack": "XapiError: SR_BACKEND_FAILURE_46(, The VDI is not available [opterr=VDI 28aaf3f0-447c-44a2-ad8e-e7c159b41ef8 not detached cleanly], )
    at Function.wrap (/usr/local/lib/node_modules/xo-server/node_modules/xen-api/src/_XapiError.js:16:12)
    at /usr/local/lib/node_modules/xo-server/node_modules/xen-api/src/transports/json-rpc.js:35:21"
}

XOA still lists the disk as present along with the other two.

I found this post, but don't want to make everything worse: https://xcp-ng.org/forum/topic/4614/help-with-vdi-cant-start-a-vm-the-vdi-is-not-available-not-detached-cleanly/5?_=1684488720911

VM details:

[11:34 xcp-ng-hv04 ~]# xe vm-list name-label=VM-Navision
uuid ( RO)           : b60762de-c222-2911-e18b-488c56e21646
     name-label ( RW): VM-Navision
    power-state ( RO): running


[11:35 xcp-ng-hv04 ~]# xe vdi-list uuid=28aaf3f0-447c-44a2-ad8e-e7c159b41ef8
uuid ( RO)                : 28aaf3f0-447c-44a2-ad8e-e7c159b41ef8
          name-label ( RW): VM-Navision-CVA - OS
    name-description ( RW):
             sr-uuid ( RO): 4da984e7-8c03-875a-0990-30a29863ee0a
        virtual-size ( RO): 161061273600
            sharable ( RO): false
           read-only ( RO): false

Was considering the below:

xe vdi-forget uuid=28aaf3f0-447c-44a2-ad8e-e7c159b41ef8 force=true
xe sr-scan uuid=4da984e7-8c03-875a-0990-30a29863ee0a
xe vbd-create device=0 vm-uuid=b60762de-c222-2911-e18b-488c56e21646 vdi-uuid=28aaf3f0-447c-44a2-ad8e-e7c159b41ef8
xe sr-scan uuid=4da984e7-8c03-875a-0990-30a29863ee0a

Latest version of XOA/XCP-NG. (xo-server 5.111.1, xo-web 5.114.0, XCP-ng 8.2.1)

Edit: Forgot to mention that the disk UUID should be the snapshot of the last backup as it's only a few hundred MB large.

Thanks

[Danp]

Have you checked under Dashboard > Health to see if there are any VDIs listed in the section VDIs attached to Control Domain?

[goreandor]

@Danp Mmmm no. Just checked. It's not there though.

[goreandor]

This was ultimately traced to a currupted metadata on the VHD and to a stuck tapdisk process on the host where the VM was running.

Solved thanks to a very persistent member of support. Thanks Jon!