[image: 1786022182703-6b58102f-353c-4da8-aed5-6817621e13e1-image.jpeg] [image: 1786022262491-a4477b40-7812-4f27-8711-917c81c818da-image.jpeg] commit 20bed SMB

@msupport Thanks for the detailed report. Please answer these questions to help us to better understand the source of the issue: What OS were the affected VMs running? Which guest tools were installed? Were the affected VDIs in VHD or QCOW2 format?

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

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?