Hi
I had exatly the same problem when I upgrade one of my four server from xenserver 7.1 to xcp-ng 8.0, one backup failed with error: job already running and the other finish normaly later!
I upgrade Xo from 5.51 to 5.54 and it's Ok for this problem BUT I have a new problem, the cold backup to NFS and the Continuous replication to a Xcp-ng 8 server are REALLY slow !! One exemple:
Start time: Thursday, December 19th 2019, 7:20:00 am
End time: Thursday, December 19th 2019, 7:58:54 am
Duration: 39 minutes
Snapshot
Start time: Thursday, December 19th 2019, 7:20:00 am
End time: Thursday, December 19th 2019, 7:20:05 am
Duration: a few seconds
SRs
Local storage (a70a93c4-4951-9bec-54ab-d45bb5039b44) ✔
Start time: Thursday, December 19th 2019, 7:20:05 am
End time: Thursday, December 19th 2019, 7:58:52 am
Duration: 39 minutes
transfer ✔
Start time: Thursday, December 19th 2019, 7:20:06 am
End time: Thursday, December 19th 2019, 7:58:50 am
Duration: 39 minutes
Size: 1.34 GiB
Speed: 605.55 KiB/s
I try to upgrade debian OS, upgrade VM (4cpus 3Go ram) but same problem for the moment
Thanks in advance
Edit: I do a manual test by copy an iso of 2G locally on the virtual machine Xen orchestra, to the same connected NFS for backup, and the performance is normal, 10 seconds for 2Go, it seems to be a problem with Xen orchestra system backup?