The problem still existed on latest as of earlier today. I removed the VM from the original (Smart Mode) backup job and cleaned up any VDI's and detached backups. As a test I created a separate backup of the VM in question pointing to the same target, this backup was successful. Hopefully I've worked around the issue, I will try adding the VM back into a Smart Mode job in the coming days.

Hi @McHenry If you still have the problem, you can increase the healthCheckTimeout value as Olivier recommended (e.g. healthCheckTimeout = ‘30m’), however this value should be in the [backups.defaultSettings] section of the configuration file (or in the [backups.vm.defaultSettings] section) rather than in the [backups] section. We've detailed the documentation a bit to make this more understandable: https://github.com/vatesfr/xen-orchestra/blob/a945888e63dd37227262eddc8a14850295fa303f/packages/xo-server/config.toml#L78-L79

Ah thanks indeed a very interesting feedback! Thanks a lot

@olivierlambert many thanks for the very quick response, it is indeed XO from sources. I think the burst explanation makes sense. Also, thanks for you and your teams continued development and support with both XCP-NG and XO.