I am seeing this message, too. This is the first time I try out delta backups. I only did one backup so far, so this is a full backup. Storage is NFS.

@dinhngtu Hi For my i made on offline Install to solve my issue, installed failed when downloading the kernel from servers, so offline install worked fine for me.

What GPU do you have? I thought I read something about NVidia's newer stuff having vGPU without the expensive licensing and hardware. But it's possible I'm just conflating that with the increase in concurrent NVENC encodes. On the bright side, you can always get a cheap GPU and just do passthrough with it. I do that for my Jellyfin server with a 2060, it's very easy to do in XCP-ng now and works super reliably.