Backup fails without printing actual error

[codingspiderfox]

I started a backup process with my newly installed Proxmox backup server as target.

Source: PVE 9.1.5

Target: PBS 4.1.0

This is the log of the backup job

INFO: starting new backup job: vzdump 105 106 --all 0 --mode snapshot --storage local --node frodo --notification-mode notification-system --notes-template '{{guestname}}' --compress zstd --fleecing 0

INFO: Starting Backup of VM 105 (qemu)

INFO: Backup started at 2026-03-20 14:15:42

INFO: status = running

INFO: VM Name: photoprism

INFO: include disk 'scsi0' 'data2TB-encrypted:vm-105-disk-0' 750G

INFO: backup mode: snapshot

INFO: ionice priority: 7

INFO: snapshots found (not included into backup)

INFO: creating vzdump archive '/var/lib/vz/dump/vzdump-qemu-105-2026_03_20-14_15_42.vma.zst'

INFO: started backup task '9582ecef-1ca7-4491-a718-9fa1cfff2d4a'

INFO: resuming VM again

INFO:   0% (257.4 MiB of 750.0 GiB) in 3s, read: 85.8 MiB/s, write: 73.1 MiB/s

INFO:   1% (7.5 GiB of 750.0 GiB) in 3m 34s, read: 35.3 MiB/s, write: 29.1 MiB/s

INFO:   2% (15.1 GiB of 750.0 GiB) in 5m 43s, read: 60.3 MiB/s, write: 29.4 MiB/s

INFO:   3% (22.6 GiB of 750.0 GiB) in 8m 45s, read: 42.0 MiB/s, write: 25.0 MiB/s

INFO:   4% (30.4 GiB of 750.0 GiB) in 13m 36s, read: 27.5 MiB/s, write: 20.0 MiB/s

INFO:   5% (38.6 GiB of 750.0 GiB) in 19m 7s, read: 25.4 MiB/s, write: 19.1 MiB/s

INFO:   6% (45.1 GiB of 750.0 GiB) in 24m 54s, read: 19.2 MiB/s, write: 17.2 MiB/s

INFO:   7% (52.5 GiB of 750.0 GiB) in 33m 23s, read: 14.9 MiB/s, write: 13.9 MiB/s

INFO:   8% (60.2 GiB of 750.0 GiB) in 40m 29s, read: 18.3 MiB/s, write: 17.6 MiB/s

INFO:   9% (67.6 GiB of 750.0 GiB) in 45m 38s, read: 24.5 MiB/s, write: 21.7 MiB/s

INFO:  10% (75.1 GiB of 750.0 GiB) in 54m 47s, read: 14.1 MiB/s, write: 13.8 MiB/s

INFO:  11% (82.7 GiB of 750.0 GiB) in 1h 1m 47s, read: 18.4 MiB/s, write: 15.5 MiB/s

INFO:  12% (90.1 GiB of 750.0 GiB) in 1h 7m 36s, read: 21.9 MiB/s, write: 20.1 MiB/s

INFO:  13% (97.6 GiB of 750.0 GiB) in 1h 12m 19s, read: 27.1 MiB/s, write: 21.9 MiB/s

INFO:  14% (106.7 GiB of 750.0 GiB) in 1h 17m, read: 33.1 MiB/s, write: 20.5 MiB/s

INFO:  15% (113.7 GiB of 750.0 GiB) in 1h 21m 52s, read: 24.6 MiB/s, write: 15.9 MiB/s

INFO:  16% (120.0 GiB of 750.0 GiB) in 1h 26m 16s, read: 24.5 MiB/s, write: 18.0 MiB/s

INFO:  17% (127.6 GiB of 750.0 GiB) in 1h 32m 56s, read: 19.3 MiB/s, write: 14.6 MiB/s

INFO:  18% (135.1 GiB of 750.0 GiB) in 1h 39m 14s, read: 20.4 MiB/s, write: 16.1 MiB/s

INFO:  19% (142.5 GiB of 750.0 GiB) in 1h 44m 27s, read: 24.4 MiB/s, write: 23.6 MiB/s

INFO:  20% (150.3 GiB of 750.0 GiB) in 1h 50m 13s, read: 23.0 MiB/s, write: 20.8 MiB/s

INFO:  21% (158.4 GiB of 750.0 GiB) in 1h 51m 2s, read: 168.1 MiB/s, write: 78.5 MiB/s

INFO:  22% (165.1 GiB of 750.0 GiB) in 1h 58m 16s, read: 15.8 MiB/s, write: 14.4 MiB/s

INFO:  23% (172.6 GiB of 750.0 GiB) in 2h 7m 14s, read: 14.3 MiB/s, write: 13.7 MiB/s

INFO:  24% (180.1 GiB of 750.0 GiB) in 2h 11m 24s, read: 31.1 MiB/s, write: 22.1 MiB/s

INFO:  25% (187.6 GiB of 750.0 GiB) in 2h 13m 5s, read: 76.1 MiB/s, write: 39.3 MiB/s

INFO:  26% (195.2 GiB of 750.0 GiB) in 2h 17m 44s, read: 27.7 MiB/s, write: 16.6 MiB/s

INFO:  27% (202.5 GiB of 750.0 GiB) in 2h 19m 56s, read: 57.0 MiB/s, write: 24.1 MiB/s

INFO:  28% (210.4 GiB of 750.0 GiB) in 2h 26m 11s, read: 21.4 MiB/s, write: 14.4 MiB/s

INFO:  29% (218.4 GiB of 750.0 GiB) in 2h 28m 21s, read: 63.3 MiB/s, write: 30.4 MiB/s

INFO:  30% (226.4 GiB of 750.0 GiB) in 2h 29m 36s, read: 108.6 MiB/s, write: 51.5 MiB/s

INFO:  31% (233.6 GiB of 750.0 GiB) in 2h 30m 2s, read: 285.7 MiB/s, write: 151.5 MiB/s

INFO:  32% (240.1 GiB of 750.0 GiB) in 2h 30m 58s, read: 117.8 MiB/s, write: 65.3 MiB/s

INFO:  33% (247.6 GiB of 750.0 GiB) in 2h 31m 59s, read: 126.4 MiB/s, write: 57.1 MiB/s

INFO:  34% (255.1 GiB of 750.0 GiB) in 2h 35m 55s, read: 32.3 MiB/s, write: 19.1 MiB/s

INFO:  35% (262.6 GiB of 750.0 GiB) in 2h 37m 48s, read: 68.0 MiB/s, write: 35.3 MiB/s

INFO:  36% (270.4 GiB of 750.0 GiB) in 2h 39m 31s, read: 78.0 MiB/s, write: 37.7 MiB/s

INFO:  37% (278.4 GiB of 750.0 GiB) in 2h 39m 57s, read: 316.4 MiB/s, write: 156.3 MiB/s

INFO:  38% (286.4 GiB of 750.0 GiB) in 2h 45m 55s, read: 22.8 MiB/s, write: 17.0 MiB/s

INFO:  39% (292.6 GiB of 750.0 GiB) in 2h 49m 43s, read: 27.7 MiB/s, write: 22.5 MiB/s

INFO:  40% (300.1 GiB of 750.0 GiB) in 2h 55m 55s, read: 20.8 MiB/s, write: 15.2 MiB/s

INFO:  41% (307.5 GiB of 750.0 GiB) in 3h 3m 47s, read: 16.0 MiB/s, write: 15.3 MiB/s

INFO:  42% (315.1 GiB of 750.0 GiB) in 3h 12m 31s, read: 14.9 MiB/s, write: 14.8 MiB/s

INFO:  43% (322.5 GiB of 750.0 GiB) in 3h 20m 59s, read: 14.9 MiB/s, write: 14.9 MiB/s

INFO:  44% (330.5 GiB of 750.0 GiB) in 3h 30m 35s, read: 14.3 MiB/s, write: 12.4 MiB/s

INFO:  45% (337.6 GiB of 750.0 GiB) in 3h 41m 13s, read: 11.3 MiB/s, write: 11.1 MiB/s

INFO:  46% (345.1 GiB of 750.0 GiB) in 3h 51m 42s, read: 12.2 MiB/s, write: 12.2 MiB/s

INFO:  47% (352.6 GiB of 750.0 GiB) in 4h 1m 42s, read: 12.7 MiB/s, write: 12.7 MiB/s

INFO:  48% (360.1 GiB of 750.0 GiB) in 4h 15m 8s, read: 9.6 MiB/s, write: 9.5 MiB/s

INFO:  49% (367.6 GiB of 750.0 GiB) in 4h 29m 13s, read: 9.2 MiB/s, write: 9.1 MiB/s

INFO:  50% (375.1 GiB of 750.0 GiB) in 4h 33m 4s, read: 33.1 MiB/s, write: 15.4 MiB/s

INFO: notified via target `mail-to-root`

TASK ERROR: job errors

 

[UdoB]

Thanks for posting the log. But... you did not tell us anything about your setup :-(

What is the source storage?
What is the destination storage? ( https://pbs.proxmox.com/docs/installation.html#recommended-server-system-requirements )
How are PVE and PBS connected? Latency?
Do you observe high load? IO-Pressure? ( head /proc/pressure/* on both PVE+PBS )
Did you take a look into the journal? ( journalctl --since "2026-03-20 14:15:42" )
You are using "--fleecing 0". You may try to enable it.

Edit:
Forget the above.

You are storing a vzdump file on your local storage??? Try to connect to PBS via Datacenter --> Storage --> Add --> Proxmox Backup Server...