@JB @gregbinsd @olivierlambert Yes restarting the tool stack works for me. I currently do not have any host offline at least not intentionally. If there is a network glitch that i am not aware of that might cause the issue if that is the actual cause. As @olivierlambert stated maybe we were having issues all along and they just changed something that is making the issue visible now. The support tunnel should still be open on my environment if you or the team want to look at logs.

So I ended up going with the Windows B&R as i could net setup the windows mount server when setting up the repo for the backups. It would setup the linux one but not the windows one. This was with using the veeam console from a windows client. So i ended up with the Windows one. Now after a few backups i am see this warning / error.... 8/5/2026 5:34:50 PM Warning : Failed to use CBT: [Task e75c4247-2ee1-7b51-088c-b970ace60f3d (Async.VDI.list_changed_blocks) failed: . SR_BACKEND_FAILURE_460. . Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated] First i thought it was because i maped the new job to older backups from Beta v1. So i purged all old backups and started fresh. The full backups were successful. Now on first delta 4 out of 7 vms have that warrning. This a Veeam issue or xcp-ng?

@jeremie1977 Ah, oui effectivement je n'ai pas testé avec plusieurs disques ! Et j'ai du typo dans la doc, je vais faire une PR pour modifier Je pense que c'est du a la façon d'insérer les disques et les DVD coté XCP-ng. Je vais investiguer !

More options: to Prevent overwriting the file: Method 1: Probably the best option. Use a Configuration Directory. Modern OpenSSH versions (8.2+) support an include directive. This is the cleanest approach. Create a drop-in file: Put your custom settings in a separate file, such as /etc/ssh/sshd_config.d/custom.conf. The rule: Package updates will not touch files inside this directory. Verification: Ensure the line Include /etc/ssh/sshd_config.d/*.conf is active at the top of your main /etc/ssh/sshd_config file. Method 2: Lock the File (Alternative) You can force the filesystem to make the file immutable so nothing can change it. Lock the file: Run sudo chattr +i /etc/ssh/sshd_config Unlock for edits: Run sudo chattr -i /etc/ssh/sshd_config when you need to make intentional changes. Method 3: Tell Apt to Ignore Updates. If you are on a Debian-based system, you can force the package manager to always keep your local version. Add this line to /etc/apt/apt.conf.d/local: UCF_FORCE_CONFFOLD=true

Filed both XO related issues: Memory visibility at VM creation: https://github.com/vatesfr/xen-orchestra/issues/10225 domain_crash invisible in XO: https://github.com/vatesfr/xen-orchestra/issues/10226 Linking to this thread as promised earlier, thanks all. Hope this helps someone out.

I have also opened a support ticket with Veeam. Well trying to... Issue with my account preventing me to and working to fix that issue. Veeam forum did make this statment about CBT and snapshots - There is one known snapshot issue that I'm guessing could possibly have this side-effect (noted in the release notes BTW). We take standard Xen snapshots for CBT but then immediately rename them with our own naming convention. We've noticed that sometimes this rename operation returns success status even if it fails. In this case I can see how this might throw this sort of error but again best to confirm w/support Veeam support ticket - 08188639

This might have worked, at that time i've allready created new VMs from the information inside the Backup xml file. It worked out allright but building VMs this way, is quite tidious. Maybe there could be a way to find the correct installer and patches, to get a new host in a state to restore a pool backup, would be good.

What kind of storage are you using? Is it a 4K block native storage? You should be able to see if you can create a virtual disk easily with xe vdi-create name-label=test virtual-size=1G sr-uuid=356475ac-…

@poddingue, that is true, my first post here. I'll try to play with these BIOS settings again. and keep you posted. Cheers

@poddingue Borrow away - "smoke alarm" is a better name for it than anything we had, so we might borrow it right back. Since you mentioned reading the matrix - here is the classification you would be reading, straight from the file: grep access: dadl/xen-orchestra.dadl | sort | uniq -c 49 access: admin 21 access: dangerous 122 access: read 75 access: write 122 of the 267 tools are plain read - that is the entire surface a review-capped agent gets. The other 145 exist in the same file, but for that agent they might as well not. The whole security taxonomy is greppable plaintext - which is rather the point of a declarative format. And if anything in the matrix looks wrong or missing, this thread is exactly the right place - real-world corrections are how it improves.

Ping @Team-OS-Platform-Release

@irtaza9 Hi ! My instinct says it can be due to XAPI timeout: https://docs.xcp-ng.org/management/manage-locally/api/#24h-task-timeout

Hi, I found your original request. I will make sure someone from the Sales team responds ASAP. Regards, Dan

If i recall from my migration I belive thats all there is to it. I know the docs mention about doing a test migration but mine just migrated and it just worked as you stated after making the needed adjustments. Let other chime in but i think you are good to go. And you could delete the snapshot from the vm.

Very cool, thanks for the feedback @maximsachs !

Hi! No, but check XO logs/output to see what's going on

My earlier wording was the problem here, not your reading of it. There are two official descriptions and they do not say the same thing. The CLI reference calls start-delay "the delay to wait before a call to start up the VM returns", which is the one I quoted. The XenAPI field description calls it "the delay to wait before proceeding to the next order in the startup sequence". That second one is exactly what you saw: the delay lands on the next VM to start, not on the one you set it on. I quoted the confusing one and then said it explained your behaviour, which it does not really. What I still cannot explain is why a start-delay would stop a VM autostarting altogether. Neither wording predicts that, so I would rather say I do not know than invent a reason. On auto_poweron_delay, I went looking and could not find it anywhere in the XCP-ng or XO docs, so I think your instinct about that search result was right. I have updated the docs PR I had open so it leads with the XenAPI wording and cites both, since the CLI reference phrasing is what sent me wrong in the first place.

Thanks for coming back with the actual cause instead of leaving it hanging. To me, a permissions reset on /etc/rc.d/rc.local would explain it completely, and it fails in the worst way, since nothing complains at boot and the VMs just never start. It also looks worth documenting, because our own troubleshooting page tells people to append a clocksource workaround to /etc/rc.local without mentioning the executable bit either, so anyone following that could end up with a workaround that quietly does nothing. I haven't tested whether the 8.2 to 8.3 upgrade resets that bit every time or just happened to in your case, so that half stays your finding, not mine. I'm curious what you turn up on the colon versus equals behaviour.

Great, thanks for the feedback!

@andriy.sultanov said: I'll try to see why other devices are omitted and how this can be fixed. Any news on this? I have been fighting with getting an Intel Arc Pro B50 to work on Linux for months and i suspect that, the fact that the audio device isn't present, is what makes Linux fail to load the driver correctly. Going the xen-cmdline way, seams to disable xe passthrough both in command line and in XO gui, causing all kinds of issues. Windows seems to be able to initialise the GPU driver without the audio device, but it is in some kind of borked state. You can send workload to the GPU but the drivers are complaining about "no-pci compatibility". XCP-ng 8.3 (latest patches) Fedora server 44 - Kernel 7.1.5-201 on latest Arc firmware as well.