Too many snapshots

McHenry

@Pilow

Thank you. I did not know this change had been made.

So now I have the master VM with a snapshot for each backup schedule.

And a CR created VM with 16 snapshots.

I wonder why the health check shows too many snapshots as I am well under 30 per VM

Pilow

@McHenry could be another cap limit on the SR
can you screenshot homepage GENERAL tab of HST150 SR ?

how many VDIs present ?
what type of SR is it ?

jr-m4

Throwing my two cents into the hat, as well.

I had a similar situation. Snapshots would't be rotated out of retention, regardless of what I set on the retention setting (on a subset of VMs ie not all of the).. The thing that solved it for my, was to recreate the affected schedule.
Do note that this will mark the previous backups taken by that technically deleted schedule, as being abandoned/orphaned.

But after I did this, snapshots would be properly rotated as expected.

McHenry

@Pilow

SR is local storage

McHenry

@jr-m4

Recreated, testing now.

McHenry

@Pilow
Was there an announcement about the change in how these CR backups are done with snapshots now?

I'd love to read up on it.

Pilow

@McHenry screenshot the GENERAL tab of "Disaster Recovery" SR please
just to see how many VDIs it hosts... at least 288

it was announced here
https://xen-orchestra.com/blog/xen-orchestra-6-3/#-backup
but it is not explaing in details, I gathered information in another topix in this forum from @florent

you also have the Changelog of 6.3.0
https://github.com/vatesfr/xen-orchestra/blob/master/CHANGELOG.md#630-2026-03-31

points to PR9524
[Replication] Reuse the same VM as an incremental replication target (PR #9524)

McHenry

@Pilow

I am rerunning the backups after recreating the schedule to see if the error clears

tjkreidl

@Pilow Yes; it's been my understanding that this has been the default for many years now.

Pilow

@tjkreidl yeah, but he has 16 snapshots.
but the documentation also talks about vdi chain length

but it seems to me impossible to have only 16 snaps and a vdi chain length >30

thats why I wondered perhaps is it a cap limit of snapshots per SR, but I didn't find relevant info about this possibility

you know a lot about Xen, ever heard of this type of per SR limit of snapshots ?
Only info I found is that more than 100/150 VDIs in production per SR can degrade performance

tjkreidl

@Pilow Yes, you are correct that the chain length is also limited. You might try to manually delete some of the snapshots and though the limit is supposed to be 30, perhaps there are other factors involved? Does that VM have a particularly large amount of storage and a lot of changes between snapshots? Are any other of your VMs experiencing similar issues? Your SR appears to be mostly empty, correct? Are there any related errors showing up in /var/log/SMlog ?