@florent Thank you.

Thank you for the update. Last night before I saw your replys that is exactly what i did. I purged the backup's for the two VMs from BackBlaze. The backup job completed successfully while copying over the previous backup images. [image: 1749549311956-screenshot-2025-06-10-055256.png]

Thanks @olivierlambert and @florent, that seems to have been the trick and fixed the issue.

@lsouai-vates Is this a description of the cause of the problem ? From what you describe, if one selects a backup containing a LVM partition scheme, it should be able to be mounted at least the first time ? As in here: I verified that this machine is using LVM first, and when selecting it, I immediately selected the large LVM partition to try to restore a file from that (which failed). [image: 1748956125525-e7148e43-aa01-433d-8af4-a936e30550e6-image.png] The machine (Debian 12) running XO do not itself use LVM, so "ubuntu-vg" should be free for mounting this first time.

This happens to me on 8.2 with one specific VM. It doesn't always happen but about once a week (it feels like) the backup will get stuck in Starting and it's always, or almost always, the same VM it's stuck on. I usually reboot the VM running XO and that makes the backup task change to Interrupted and then the next scheduled backup usually works. Would be nice to know if there's something that's causing this that I can try to fix. Not a world-ending problem but it's a nuisance since it stops all future backups for that Job until it's resolved. I'm happy that all the other VMs in that job get backed up at least.

I created a new CR job for another VM and it worked. However, it didn't work with the XO VM. So maybe the root cause of the problem is that the old CR copies have disappeared. Maybe they still exist, but I can't find them?

@ph7 I ask the XO team about it, thanks for the report.

@syscon-chrisl Note that when changing the management interface, it's highly recommended to reduce the PMI down to just one NIC on all your hosts before you make the change. That said, it's always a scary thing to do and as others have stated, best avoided if at all possible. Making sure all hosts are at the same hotfix levelasand that their NICs are all in the same order and speeds are essential requirements.

@yeopil21 Run top, xentop, and iostat to see if dom0 and.or the storage device might be a bottleneck. The configuration of your storage device can also be a big factor, and in some casaes, various performance tweaks are possible. The specific configuration would be helpful: connectivity (NFS, fibre channel, iSCSI), number and size and speeds of disks, RAID configuration, total number of VMs resident on the device, number of independent SRs, provisioning (thin or thick), network (if not fibre channel) speed and settings. STorage optimization is a bit of an art and in many cases, can be the limiting factor, but as stated, so can the lack of dom0 resources. Also, what clock speed and number of CPUs are on your hosts?

That's great, those are companies with 100% backup dedicated products We cannot be everywhere and we have to prioritize on what most people expect. Recovery capabilities on a second site is like one of the most needed feature, that's why we did CR. From a technical stand point, when a VM is replicated, it's on another SR and XO doesn't have any direct access to the SR to mount it. IDK how VEEAM is doing, likely accessing the SR or similar (at least not on XCP-ng )

@kosa7 from what the XO devs told me : for now you have to handle it completly manually, since we have separated collection a not a relationnal db... You could maybe use a smart mode backup with a VM tag. We plan to implement a relational database in the future, which would at least offer the possibility to handle this. "Reasonnably : warm migration should be more a one off , so the user must handle the consequence. If he uses this regularly, he should add a tag to the VM " DBPRODBACKUPPLZ" and then configure his job to use this tag" FYI @olivierlambert

@olivierlambert Indeed, xe vm-export uuid=<uuid of the vm> filename=/<path>/backup.xva exports the current disk state. Thank you.

@olivierlambert yes, I started to work on friday, and hopefully will have a fix today

@lsouai-vates P.S. This HAS been working a while ago!! I just noticed that it broke when there was a backup job, which had an error and I didn't receive an email. So I can't say when the issue started.

@henri9813 hello, thnaks for the feedback. I propose that you open a git feature in xen orchestra project so we can add it to our roadmap. Have a good day

Changing python system wide on XCP-ng shows that the appliance nature of XCP-ng is really not well understood.

@McHenry hello, thanks for the report. Can you open a suggestion on Github so we can plan it or next roadmap? Have a good day.