Backup failed with obscure error message

[Aimdev]

I built XO today, no errors.
I then exported a VM, no issues.
I then exported another VM, and got this message

 Snapshot 
Start: Sep 22, 2021, 12:20:51 PM
End: Sep 22, 2021, 12:20:51 PM
Error: VM_HAS_VUSBS(OpaqueRef:4656aff6-d202-4e6e-83e2-b40e52208203)
Start: Sep 22, 2021, 12:20:51 PM
End: Sep 22, 2021, 12:20:51 PM
Duration: a few seconds
Error: VM_HAS_VUSBS(OpaqueRef:4656aff6-d202-4e6e-83e2-b40e52208203)

All backups via SMB to Truenas (NFS I cannot get to work)
The VM in question has pass thru for a Ublox usb GPS receiver.

Hypervisor for the succesfull backup is 8,1, for the failed backup 8.2 (fresh install)

[Danp]

@aimdev said in Backup failed with obscure error message:

VM_HAS_VUSBS

https://github.com/xcp-ng/xcp/issues/164

ghost created this issue in xcp-ng/xcp

open Enable snapshots for VM with vUSB/USB passthrough #164

[Aimdev]

@danp

Thanks, comment raised on github.

[olivierlambert]

So in your case, there's nothing related to XCP-ng version (8.1 vs 8.2), it's due to the USB passthrough enabled, as @Danp said.

[Aimdev]

@olivierlambert
Using the old backup system, based on bash/cron never had an issue from pre xpp-ng to 8.2.
Trying out XOA to see if the backup regime would be easier to administer for other users, it failed on the VM with USB.
I do not know if the issue is with 8.1 or 8.2 as I never tested backup with XOA until I installed 8.2 this week.
I also do not know if it is an XOA issue.
You know my thoughts on USB handling as I have commented many times.

[olivierlambert]

The issue is to snapshot the VM while there's USB passthrough. Offline backup might work, please try.