help needed: "No buffer space available" error after backup

[rolaja_ke]

Dear community,

I'm facing a critical issue with my Proxmox VE setup and could really use your expertise to resolve it.
Here's a brief overview:

I recently installed Proxmox VE and had iobroker running smoothly in an LXC container for a day or two. However, when I attempted to create a backup, I encountered a "No Buffer Space Available" error.

The syslog in Proxmox VE looks like - see below
RAM and HDD should be plenty around - also see below.

I am unable to start or perform any actions with the LXC. Additionally, when I mouse over the node in the Proxmox web UI, I receive the following message: Status unknown, Config locked (backup)



Apparently something went wrong with the backup.
I would highly appreciate any solutions, hints, or thoughts you may have regarding this error. It's causing a significant disruption, and any assistance would be invaluable.

Thank you all in advance for your time and support.

Best regards,
rolaja





Nov 15 08:38:32 proxmox pvedaemon[184513]: INFO: Starting Backup of VM 223 (lxc)
Nov 15 08:38:32 proxmox dmeventd[302]: No longer monitoring thin pool pve-data-tpool.
Nov 15 08:38:32 proxmox dmeventd[302]: Monitoring thin pool pve-data-tpool.
Nov 15 08:38:32 proxmox kernel: EXT4-fs (dm-7): write access unavailable, skipping orphan cleanup
Nov 15 08:38:32 proxmox kernel: EXT4-fs (dm-7): mounted filesystem b53676a8-d510-4249-9f23-46b2512c8e9c without journal. Quota mode: none.
Nov 15 08:38:36 proxmox kernel: EXT4-fs (dm-7): unmounting filesystem b53676a8-d510-4249-9f23-46b2512c8e9c.
Nov 15 08:38:36 proxmox kernel: dm-7: detected capacity change from 67108864 to 0
Nov 15 08:38:36 proxmox pvedaemon[184513]: ERROR: Backup of VM 223 failed - command 'set -o pipefail && lxc-usernsexec -m u:0:100000:65536 -m g:0:100000:65536 -- tar cpf - --totals --one-file-system -p --sparse --numeric-owner --acls --xattrs '--xattrs-include=user.*' '--xattrs-include=security.capability' '--warning=no-file-ignored' '--warning=no-xattr-write' --one-file-system '--warning=no-file-ignored' '--directory=/var/lib/vz/dump/vzdump-lxc-223-2023_11_15-08_38_32.tmp' ./etc/vzdump/pct.conf ./etc/vzdump/pct.fw '--directory=/mnt/vzsnap0' --no-anchored '--exclude=lost+found' --anchored '--exclude=./tmp/?*' '--exclude=./var/tmp/?*' '--exclude=./var/run/?*.pid' ./ | zstd '--threads=1' >/var/lib/vz/dump/vzdump-lxc-223-2023_11_15-08_38_32.tar.dat' failed: interrupted by signal
Nov 15 08:38:36 proxmox pvedaemon[184513]: INFO: Backup job finished with errors
Nov 15 08:38:36 proxmox pvedaemon[184513]: job errors
Nov 15 08:38:36 proxmox pvedaemon[183692]: <root@pam> end task UPIDroxmox:0002D0C1:005D3177:65547578:vzdump:223:root@pam: job errors
Nov 15 08:38:44 proxmox pvedaemon[183692]: <root@pam> starting task UPIDroxmox:0002D12B:005D365C:65547584:vzdump:223:root@pam:
Nov 15 08:38:44 proxmox pvedaemon[184619]: INFO: starting new backup job: vzdump 223 --mode snapshot --notes-template '{{guestname}}' --node proxmox --remove 0 --compress zstd --storage local
Nov 15 08:38:44 proxmox pvedaemon[184619]: INFO: Starting Backup of VM 223 (lxc)
Nov 15 08:38:45 proxmox dmeventd[302]: No longer monitoring thin pool pve-data-tpool.
Nov 15 08:38:45 proxmox dmeventd[302]: Monitoring thin pool pve-data-tpool.
Nov 15 08:38:52 proxmox pvedaemon[184619]: No buffer space available
Nov 15 08:38:52 proxmox pvedaemon[184619]: No buffer space available
Nov 15 08:38:52 proxmox pvedaemon[184619]: ERROR: Backup of VM 223 failed - No buffer space available
Nov 15 08:38:52 proxmox pvedaemon[184619]: INFO: Backup job finished with errors

 

[LnxBil]

That's not good:

Nov 15 08:38:32 proxmox kernel: EXT4-fs (dm-7): write access unavailable, skipping orphan cleanup
Nov 15 08:38:32 proxmox kernel: EXT4-fs (dm-7): mounted filesystem b53676a8-d510-4249-9f23-46b2512c8e9c without journal. Quota mode: none.
Nov 15 08:38:36 proxmox kernel: EXT4-fs (dm-7): unmounting filesystem b53676a8-d510-4249-9f23-46b2512c8e9c.
Nov 15 08:38:36 proxmox kernel: dm-7: detected capacity change from 67108864 to 0

Please post the output of dmesg in CODE-Tags or attach the file.

 

[rolaja_ke]

please find attached

 

[LnxBil]

please find attached

Thank you, please post the output of the command AFTER a problem occured. The system seems to be just restarted, hasn't it? If not, the bottom of the file is missing.