Thank you every visitors and for those who did not had the chance to visit fosdem check this report:
https://xcp-ng.org/blog/2026/02/19/fosdem-2026-follow-up/
[image: vates-xcp-ng-at-fosdem-2026-1.webp]
One question, I promised to forward to the forum, how many VM are you running on XCP-ng ?
Dozen, hundreds, thousands or more ?
@nikade said in Every virtual machine I restart doesn't boot.:
@DustinB yeah im guessing the VDI isn't attached to the VM for some reason, based on the screenshot.
Im also wondering if he ever rebooted the VM's after installing them with PXE
Right, it's a likely answer... but even then I would've expected his PXE server to just restart the installation process all over again... assuming that the disk is attached to the VM etc and that PXE boot isn't disabled automatically like it is with an ISO after first boot.
haha
@Pa3docypris I also had this problem with one single Debian VM. I would delete the snapshot and they would just keep adding every backup. I have lots of the same VMs and lots of other VMs on the pool. Three VMs were basically exactly the same but only one had an issue.
I tried deleting all snapshots on the VM. Changing the CBT state. Doing a full backup up of the VM.... same problem. Snapshots just built up.
I found a CD in the VM drive and it would not eject (with a XCP error). So there was something strange with the VM state. I shutdown the VM, cleared the CD, and restarted the VM. After that, backups worked normally for that VM. So I won't blame XCP or XO, it seems the VM was just in a random strange state that caused problems.
Difficile de parler de « réalité » avec les benchmarks. Vérifiez aussi l'iodepth (qui dépend du type matériel que vous avez, sur du flash/NVMe vous pouvez monter à 128 ou 256), la latence entre en compte aussi bien sûr.
Le bottleneck principal est le monothreading de tapdisk, si vous testez sur plusieurs VMs différentes la somme va monter de manière assez régulière.
