S3 backup and encryption

[jonas]

Hi,

I'm testing S3 backups. It's a real nice feature.


I have no problem running backups with enryption. But when I add encryption backup get stuck.
The PBS software stops working, complete hangs. No respons from web gui. I need to restart.
PBS server is up and running, can login with SSH.

Here is the log from when it happaned.


INFO: starting new backup job: vzdump 102 110 108 300 500 667 3001 107 --notes-template '{{guestname}}' --prune-backups 'keep-daily=7,keep-last=4,keep-monthly=12' --mode snapshot --notification-mode notification-system --node pve01 --storage pbs01-s3-pve01 --fleecing 0 --all 0
INFO: Starting Backup of VM 102 (qemu)
INFO: Backup started at 2025-12-02 16:17:22
INFO: status = running
INFO: VM Name: nginx-proxy-1
INFO: include disk 'virtio0' 'SSD1:vm-102-disk-0' 6G
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: creating Proxmox Backup Server archive 'vm/102/2025-12-02T15:17:22Z'
INFO: issuing guest-agent 'fs-freeze' command
ERROR: unable to freeze guest fs - failed to freeze /: Input/output error
INFO: issuing guest-agent 'fs-thaw' command
INFO: started backup task 'c3f397ae-f389-41b8-956f-4c3b190934e8'
INFO: resuming VM again
INFO: virtio0: dirty-bitmap status: existing bitmap was invalid and has been cleared
INFO: 18% (1.1 GiB of 6.0 GiB) in 3s, read: 369.3 MiB/s, write: 206.7 MiB/s
INFO: 32% (2.0 GiB of 6.0 GiB) in 6s, read: 298.7 MiB/s, write: 298.7 MiB/s
INFO: 48% (2.9 GiB of 6.0 GiB) in 9s, read: 333.3 MiB/s, write: 326.7 MiB/s
INFO: 57% (3.5 GiB of 6.0 GiB) in 12s, read: 182.7 MiB/s, write: 176.0 MiB/s
INFO: 73% (4.4 GiB of 6.0 GiB) in 15s, read: 317.3 MiB/s, write: 277.3 MiB/s
INFO: 83% (5.0 GiB of 6.0 GiB) in 18s, read: 217.3 MiB/s, write: 190.7 MiB/s
INFO: 90% (5.4 GiB of 6.0 GiB) in 21s, read: 140.0 MiB/s, write: 130.7 MiB/s
INFO: 94% (5.7 GiB of 6.0 GiB) in 24s, read: 70.7 MiB/s, write: 69.3 MiB/s
INFO: 95% (5.7 GiB of 6.0 GiB) in 27s, read: 29.3 MiB/s, write: 29.3 MiB/s
INFO: 97% (5.8 GiB of 6.0 GiB) in 31s, read: 26.0 MiB/s, write: 26.0 MiB/s
INFO: 100% (6.0 GiB of 6.0 GiB) in 34s, read: 54.7 MiB/s, write: 45.3 MiB/s
INFO: backup is sparse: 564.00 MiB (9%) total zero data
INFO: backup was done incrementally, reused 788.00 MiB (12%)
INFO: transferred 6.00 GiB in 64 seconds (96.0 MiB/s)
INFO: adding notes to backup
INFO: prune older backups with retention: keep-daily=7, keep-last=4, keep-monthly=12
INFO: running 'proxmox-backup-client prune' for 'vm/102'
INFO: pruned 0 backup(s)
INFO: Finished Backup of VM 102 (00:01:05)
INFO: Backup finished at 2025-12-02 16:18:27
INFO: Starting Backup of VM 107 (qemu)
INFO: Backup started at 2025-12-02 16:18:27
INFO: status = running
INFO: VM Name: hogberg
INFO: include disk 'scsi0' 'SSD1:vm-107-disk-0' 600G
INFO: exclude disk 'scsi1' 'SATA2:vm-107-disk-1' (backup=no)
INFO: exclude disk 'scsi2' 'USB1:vm-107-disk-0' (backup=no)
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: creating Proxmox Backup Server archive 'vm/107/2025-12-02T15:18:27Z'
INFO: issuing guest-agent 'fs-freeze' command
INFO: issuing guest-agent 'fs-thaw' command
INFO: started backup task 'b78b4093-b217-4ecf-8812-2bf95a2d94f8'
INFO: resuming VM again
INFO: scsi0: dirty-bitmap status: created new
INFO: 0% (464.0 MiB of 600.0 GiB) in 3s, read: 154.7 MiB/s, write: 116.0 MiB/s
ERROR: interrupted by signal
INFO: aborting backup job
INFO: resuming VM again
ERROR: Backup of VM 107 failed - interrupted by signal
INFO: Failed at 2025-12-02 16:19:10
ERROR: Backup job failed - interrupted by signal
INFO: notified via target `mail-to-root`
TASK ERROR: interrupted by signal

 

[Chris]

Hi,
please post the output of proxmox-backup-manager version --verbose and make sure you are running the latest version of proxmox-backup-server. Also, if you have the 6.17 kernel and the network configured with MTU 9000, see if the issue persists if you either downgrade to an older kernel version or reconfigure to use the default MTU. See https://forum.proxmox.com/threads/s...r-updated-to-pve-9-1-1-and-pbs-4-0-20.176444/

 

[jonas]

I run MTU 9000

Kernel is now downgraded and it seem to work.

root@pbs01:~# proxmox-backup-manager version --verbose
proxmox-backup 4.0.0 running kernel: 6.14.8-2-pve
proxmox-backup-server 4.1.0-1 running version: 4.1.0
proxmox-kernel-helper 9.0.4
proxmox-kernel-6.17.2-1-pve-signed 6.17.2-1
proxmox-kernel-6.17 6.17.2-2
proxmox-kernel-6.14.11-4-pve-signed 6.14.11-4
proxmox-kernel-6.14 6.14.11-4
proxmox-kernel-6.14.8-2-pve-signed 6.14.8-2
proxmox-kernel-6.8.12-13-pve-signed 6.8.12-13
proxmox-kernel-6.8 6.8.12-13
proxmox-kernel-6.8.12-1-pve-signed 6.8.12-1
proxmox-kernel-6.5.13-6-pve-signed 6.5.13-6
proxmox-kernel-6.5 6.5.13-6
proxmox-kernel-6.5.11-6-pve-signed 6.5.11-6
ifupdown2 3.3.0-1+pmx11
libjs-extjs 7.0.0-5
proxmox-backup-docs 4.1.0-1
proxmox-backup-client 4.1.0-1
proxmox-mail-forward 1.0.2
proxmox-mini-journalreader 1.6
proxmox-offline-mirror-helper 0.7.3
proxmox-widget-toolkit 5.1.2
pve-xtermjs 5.5.0-3
smartmontools 7.4-pve1
zfsutils-linux 2.3.4-pve1
root@pbs01:~#

Thank you!

 

[Chris]

If you are not using ZFS, please consider testing different mainline kernels as well, that would help us a lot in narrowing down the issue https://forum.proxmox.com/threads/s...o-pve-9-1-1-and-pbs-4-0-20.176444/post-820364

 

[jonas]

I can't get those kernels to work. I will try more later.

 

[Chris]

What root filesystem do you use?

 

[jonas]

ext4 on top of lvm.