XCP-ng 8.3 updates announcements and testing

[Emmanuel V]

Some message formats changed between the two releases, so VMs started before the update (with an 11.3 tapdisk and tapback) can’t understand some of the changed commands. Rebooting XCP-ng or doing an RPU should work. Since not every command is affected, restarting tapback is usually enough: systemctl restart tapback.service
We're going to work to avoid that.

[jr-m4]

@Emmanuel-V

Rebooting hosts and/or VMs doesn't solve the problems.
As @andrew said. This one got ugly. But this is also why we test stuff

Update:
Doing a "Rescan all disks" on the SR (lvmohba), seems to help out a little bit. But not everything.
Some VMs were able to be started again. But others are still showing problems and erroring out

"The VDI is not available [opterr=['MAP_DUPLICATE_KEY', 'VDI', 'sm_config', 'OpaqueRef:7---------2c1b', 'activating']]",

[flakpyro]

@jr-m4 I had this issue on one of the pools i tested on as well and was able to fix the issue by following the fix here:
https://xcp-ng.org/forum/topic/10603/sr_backend_failure_46-the-vdi-is-not-available-not-detached-cleanly/3

[dthenot]

@flakpyro Hello,

It would be preferred to use another method.
You can use the resetvdis.py script in the /opt/xensource/sm/ to reset values instead,
using vdi-forget is unadvised in this case, it can cause issues by losing information that are stored in XAPI about VDIs.

/opt/xensource/sm/resetvdis.py single <VDI UUID>

[jr-m4]

@dthenot said:

@flakpyro Hello,

It would be preferred to use another method.
You can use the resetvdis.py script in the /opt/xensource/sm/ to reset values instead,
using vdi-forget is unadvised in this case, it can cause issues by losing information that are stored in XAPI about VDIs.

/opt/xensource/sm/resetvdis.py single <VDI UUID>

I was just about to look at maybe doing what @flakpyro suggested. More likely I would've just restored from backup. As this is dev-instances, and non-important.

But your resetvdis.pysuggestion solved it entirely! Thanks for the quick tip!

[jr-m4]

Now trying to see if pool works with generic operations.

Trying to do a RPR on new-xcp-dev. And I'm met with

Ofcourse there are no backups being run. They are even disabled right now. And the only active task happening is "Garbage collection" on the main SR.

pool.rollingReboot
{
  "pool": "1f16dad2---------------6c8b8b7",
  "bypassBackupCheck": false,
  "shutdownPinnedVms": false
}
{
  "code": "CANNOT_EVACUATE_HOST",
  "params": [
    "VM_LACKS_FEATURE,OpaqueRef:aa5210c4-a------------1b80-9bca5d0d0f8d|OPERATION_BLOCKED,OpaqueRef:c7a08---------------a0--------------9306,VM migration is blocked during backup"
  ],
  "call": {
    "duration": 23,
    "method": "host.assert_can_evacuate",
    "params": [
      "* session id *",
      "OpaqueRef:0145019c-2a32-13bb-5951-3bca9e59e63a"
    ]
  },
  "message": "CANNOT_EVACUATE_HOST(VM_LACKS_FEATURE,OpaqueRef:aa52-----------------------9bca5d0d0f8d|OPERATION_BLOCKED,OpaqueRef:c7a0------------------------306,VM migration is blocked during backup)",
  "name": "XapiError",
  "stack": "XapiError: CANNOT_EVACUATE_HOST(VM_LACKS_FEATURE,OpaqueRef:aa521-------------------8d|OPERATION_BLOCKED,OpaqueRef:c7a08c--------------------------9306,VM migration is blocked during backup)
    at XapiError.wrap (file:///opt/xen-orchestra/packages/xen-api/_XapiError.mjs:16:12)
    at file:///opt/xen-orchestra/packages/xen-api/transports/json-rpc.mjs:38:21
    at runNextTicks (node:internal/process/task_queues:65:5)
    at processImmediate (node:internal/timers:541:9)"
}

Update:
I believe this might be related due to a VDI being orphaned, and trying to delete it results in VDI_NOT_MANAGED-error. Trying a new rescan of disks on the SR, and hopefully garbage collection will finish until Monday. Otherwise I will somehow try to forcefully destroy this VDI.

Update 2:
Managed to do a RPR now.
Seems that the flag "Prevent Migration" was applied to one of the VMs. My guess is that this is applied when backups are taken. And since the backups broke with the updates. The flag never got cleared.
I did a quick visual confirmation to see that my guess of this behaviour seems correct. And it indeed sets the "Prevent migration"-flag whilst the backup runs.

Running backups on my pools to see if functionality is working as intended again.

Update 3:
Maybe related, maybe not. But my backup-tests are piling up with lots of VBD.unplug_force, that have gone on for <=30 minutes. And this is on both pools. And it seems very much so that the backup-jobs doesn't complete properly. This could also be entirely XO-related, since there has been several commits towards backups as well.

Update 4:
Updated XO from source to the latest commit d2ffe, and things have not improved.
Pretty much, many actions with VDIs are problematic. I'll happily provide logs. But will only do so if I get somewhere to upload them to.
I'll be taking the weekend now. So won't be able to respond before monday,

[JeffBerntsen]

Updated and running on my test pool and twinstor test pair. I don't use XO for backups so I'm not seeing the possible issues associated with that but all else seems to be running just fine.

[gduperrey]

The storage and XAPI teams are currently investigating the issues that have been reported.

There is no final solution yet, but we are getting closer. Unfortunately, there is no ETA at this time.

Thank you very much for all your testing and feedback!

[olivierlambert]

Thanks everyone for testing! As you can all see here, it’s been extremely useful

[acebmxer]

I have been doing more testing and if it is not known yet I belive this issue happens when the VDIs are in QCOW2 format. When using VHD I have no issues with backup jobs runing and completing when using NBD and CBT while the jobs hang previously when backing up a QCOW2 vdi.
2026-10-24T22_35_02.931Z - backup NG.txt