Missing vdi which is a base for a delta
-
Our mirror backup jobs continue to fail about 50% of the VMs with this Missing vdi which is a base for a delta error. I have deleted the data from the remote(s) and the problem comes right back. I'm not sure what is causing it. The backups on the source remote pass health checks.
-
I've just removed ALL the backups for one VM and created a new Full backup; When I run the mirror job it again says Missing vdi f04fb96a-5923-4c75-bb42-6c916497885c which is a base for a delta.
-
Are you using XOA or XO from sources? If the later what Commit are you on? Did you install the recent beta updates for your hosts?
Can you post the log of the the failed backups.
-
The same error came up last year (https://xcp-ng.org/forum/topic/11086/how-do-i-diagnose-a-missing-vdi-error-with-mirror-backups), and @florent's advice there was to delete the most recent backups of the failing VM on the mirror target, so they get transferred again from the source.
You already wiped the target and it came back, so I suspect yours is a different case, but I don't know the mirror code well enough to say why.
The XO version and the job log @acebmxer asked for would narrow it down, and with those it might be one for @Team-XO-Backend. -
P poddingue marked this topic as a question
-
@poddingue Yes, thanks, I reviewed that post.
-
@acebmxer Of course, sorry. We have XO from sources, currently commit 0be90. I'm not aware of any beta updates? I'm attaching the latest log for one of the jobs.
2026-10-27T06_00_00.022Z - backup NG.json.txt -
@blueh2o thanks for the log. In that run 16 of the 56 VMs failed this way, and each one names a different missing base, so it doesn't look like one damaged chain to me.
That's past what I can work out on my own, so @Team-XO-Backend, this one has a version and a full job log attached above now if someone can take a look. -
FWIW it seems to be the same VMs and same VDIs each day. I'm doing some additional experimentation and testing.
-
@blueh2o same VMs and same disks every day is useful, I think, since whoever looks at it can then trigger it on demand instead of waiting for a bad night.
While you experiment, do the failing VMs have something in common? The same source SR, for example, or a mirror target keeping a different retention than the source.
I don't know the mirror code well enough to say which of those would matter.
-
While you experiment, do the failing VMs have something in common? The same source SR, for example, or a mirror target keeping a different retention than the source.
There are two backup jobs that are failing. One from Ark (local) to Synology, and one from Ark to S3. It seems to be the same VMs failing each night, but interestingly, there are some that fail to Synology but succeed to S3 and vice-versa. There are 9 VMs that fail for both. They do not all share the same SR. The backups on Ark are coming from several delta jobs that run daily, weekly, and monthly. Retention are different for all those.
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login