Backups failed after server 4.1.8, client 4.1.9 updates

[khe91]

VM 202
INFO: Error: upload failed: error at "var/cache/apparmor/29ff1d9f.0/usr.sbin.tcpdump-RXsIDo"
VM 206
INFO: Error: upload failed: error at "var/cache/apparmor/2693c843.0/nvidia_modprobe-l8oMqr"
VM 207
INFO: Error: upload failed: error at "var/cache/apparmor/7a03f264.0/nvidia_modprobe-QIS9FQ"
VM 300
INFO: Error: upload failed: error at "var/cache/apparmor/7a03f264.0/nvidia_modprobe-jI7R38"

Worked fine before the latest updates.
All Ubuntu 22.04 LTS vm's.
Backups to CIFS of the same vm's worked without errors, just to PBS server 4.1.8. gives the errors. Backups to PBS 4.1.6 work too.

 

[Chris]

Please share the full backup task logs and the vm configs, thanks.

 

[khe91]

Please share the full backup task logs and the vm configs, thanks.

One example:

INFO: starting new backup job: vzdump 300 --mode stop --node pve2 --notes-template '{{guestname}}' --remove 0 --storage pbs100G --notification-mode notification-system
INFO: Starting Backup of VM 300 (lxc)
INFO: Backup started at 2026-04-25 16:29:38
INFO: status = stopped
INFO: backup mode: stop
INFO: ionice priority: 7
INFO: CT Name: dev
INFO: including mount point rootfs ('/') in backup
INFO: creating Proxmox Backup Server archive 'ct/300/2026-04-25T14:29:38Z'
/dev/rbd6
INFO: set max number of entries in memory for file-based backups to 1048576
INFO: run: /usr/bin/proxmox-backup-client backup --crypt-mode=none pct.conf:/var/tmp/vzdumptmp112210_300/etc/vzdump/pct.conf root.pxar:/mnt/vzsnap0 --include-dev /mnt/vzsnap0/./ --skip-lost-and-found --exclude=/tmp/?* --exclude=/var/tmp/?* --exclude=/var/run/?*.pid --backup-type ct --backup-id 300 --backup-time 1777127378 --change-detection-mode metadata --entries-max 1048576 --repository fritz@pam@192.xxx.yyy.54bs_zfs1 --ns pve2
INFO: Starting backup: [pve2]:ct/300/2026-04-25T14:29:38Z
INFO: Client name: pve2
INFO: Starting backup protocol: Sat Apr 25 16:29:38 2026
INFO: Downloading previous manifest (Thu Apr 23 20:00:57 2026)
INFO: Upload config file '/var/tmp/vzdumptmp112210_300/etc/vzdump/pct.conf' to 'fritz@pam@192.xxx.yyy.54:8007bs_zfs1' as pct.conf.blob
INFO: Upload directory '/mnt/vzsnap0' to 'fritz@pam@192.xxx.yyy.54:8007bs_zfs1' as root.mpxar.didx
INFO: Using previous index as metadata reference for 'root.mpxar.didx'
INFO: unclosed encoder dropped
INFO: closed encoder dropped with state
INFO: unfinished encoder state dropped
INFO: root.ppxar: reused 2.184 GiB from previous snapshot for unchanged files (1263 chunks)
INFO: root.ppxar: had to backup 63.472 MiB of 2.596 GiB (compressed 21.534 MiB) in 8.61 s (average 7.373 MiB/s)
INFO: root.ppxar: backup was done incrementally, reused 2.534 GiB (97.6%)
INFO: Error: upload failed: error at "var/cache/apparmor/7a03f264.0/nvidia_modprobe-jI7R38"
ERROR: Backup of VM 300 failed - command '/usr/bin/proxmox-backup-client backup '--crypt-mode=none' pct.conf:/var/tmp/vzdumptmp112210_300/etc/vzdump/pct.conf root.pxar:/mnt/vzsnap0 --include-dev /mnt/vzsnap0/./ --skip-lost-and-found '--exclude=/tmp/?*' '--exclude=/var/tmp/?*' '--exclude=/var/run/?*.pid' --backup-type ct --backup-id 300 --backup-time 1777127378 --change-detection-mode metadata --entries-max 1048576 --repository fritz@pam@192.xxx.yyy.54bs_zfs1 --ns pve2' failed: exit code 255
INFO: Failed at 2026-04-25 16:29:47
INFO: Backup job finished with errors
INFO: notified via target `mail-to-root`
TASK ERROR: job errors

arch: amd64
cores: 1
features: nesting=1
hostname: dev
memory: 2048
nameserver: 192.xxx.yyy.40
net0: name=eth0,bridge=vmbr0,gw=192.xxx.yyy.1,hwaddr=D21:B1:00:CE:9A,ip=192.xxx.yyy.64/24,type=veth
ostype: ubuntu
rootfs: ceph:vm-300-disk-0,size=10G,mountoptions=discard
searchdomain: intranet.zzz.de
swap: 512
tags:
lxc.cgroup2.devices.allow: c 10:200 rwm
lxc.mount.entry: /dev/net dev/net none bind,create=dir

 

[Chris]

Please try to get some debug output by running PBS_LOG=debug vzdump 300 --storage pbs100G --pbs-change-detection-mode=metadata | tail -n 300 > client-debug.log and attach the generated file here. Note that this will most likely contains some directory and filenames, so retract if required.