CBT disabling itself / bug ?
-
Hi,
Latest XOA, with fully patched XCP 8.3 here.
I'm fiddling around again with NBD+CBT in backup jobs (was avoiding CBT for a time, to reliably control my backups and avoid unnecessary KEY points) in the context of THICK SRs to spare some space.
I know that CBT is reset when migrating from one SR to another.
But here is what I encounter :
- VM has no CBT enabled on its VDIs, it is on a SHARED SR in a pool of 3 hosts
- backup option changed for NBD+CBT, was only NBD before
- CBT is enabled on the next run by the backup job, I get a delta (was expecting a FULL ?)
- next run, delta, as expected
- i migrate this VM on another HOST, without changing its SR
- CBT is immediatly disabled ? why ??
- next run of backup it tries a delta, but "fall back to a full" (normal as CBT has been disabled...), and do a KEY point on the remote
- next run is a delta as expected
does this mean if I do a rolling pool update or host maintenance that will move the all VMs around, all CBT will be disabled and I should expect a FALL BACK TO FULL on all my NBD+CBT enabled backup jobs ??!
why disabling CBT on a change of HOST and no move of SR ?
-
@Pilow Sounds very similar to my experiences with CBT.
Check out my post here (and keep reading from that point down)
https://xcp-ng.org/forum/post/88968Can you check with the same commands i used?
-
@flakpyro indeed seems related.
I also have this bug :
on some VMs all jobs do KEY points, but in the backup logs they are indeed DELTA
you can see as mere Megabytes are transfered that it's a delta backup... but point is presented as KEY
here is the log :
-
about these KEY backups, I think perhaps LTR got in the way @florent @bastien-nollet
still no way of knowing WHEN a weekly/monthly backup is happening ?