Backup failure on a specific container

notlily

New Member
Aug 17, 2025
3
0
1
I have a ProxmoxVE Sever attempting to backup to a ProxmoxBS Server. When I initiate a backup it will partially succeed, 1 container always fails.

According to ProxmoxVE, the backup failed with these lines in the task,
Code:
INFO: processed 6.04 GiB in 2m, uploaded 5.786 GiB
INFO: unclosed encoder dropped
INFO: closed encoder dropped with state
INFO: unfinished encoder state dropped
INFO: finished encoder state with errors
INFO: catalog upload error - channel closed   
INFO: Error: failed to upload chunk to s3 backend
INFO: cleanup temporary 'vzdump' snapshot
  Logical volume "snap_vm-301-disk-0_vzdump" successfully removed.
  Logical volume "snap_vm-301-disk-0_vzdump" successfully removed.
ERROR: Backup of VM 301 failed - command 'lxc-usernsexec -m u:0:100000:65536 -m g:0:100000:65536 -- /usr/bin/proxmox-backup-client backup '--crypt-mode=encrypt' '--keyfd=15' pct.conf:/var/tmp/vzdumptmp305213_301/etc/vzdump/pct.conf root.pxar:/mnt/vzsnap0 --include-dev /mnt/vzsnap0/./ --include-dev /mnt/vzsnap0/./mnt --skip-lost-and-found '--exclude=/tmp/?*' '--exclude=/var/tmp/?*' '--exclude=/var/run/?*.pid' --backup-type ct --backup-id 301 --backup-time 1755383844 --entries-max 1048576 --repository root@pam@192.168.1.64:backblaze-b2' failed: exit code 255
INFO: Failed at 2025-08-16 18:39:30
INFO: Backup job finished with errors
INFO: notified via target `mail-to-root`
TASK ERROR: job errors

ProxmoxBS says
Code:
2025-08-16T18:39:27-04:00: POST /dynamic_chunk
2025-08-16T18:39:27-04:00: backup ended and finish failed: backup ended but finished flag is not set.
2025-08-16T18:39:27-04:00: removing unfinished backup
2025-08-16T18:39:27-04:00: Upload of new chunk cba0523cf0909e284169e34c33b1518df6080b54130c738381210cf5d175c895
2025-08-16T18:39:27-04:00: removing backup snapshot "/mnt/datastore/backblaze-b2/ct/301/2025-08-16T22:37:24Z"
2025-08-16T18:39:27-04:00: TASK ERROR: backup ended but finished flag is not set.

I am backing up from a Arch Linux container to Backblaze B2.