How much free space is needed to backup VM/LXC ?

why-be-banned

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Apr 4, 2023
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How much free space is needed to backup VM/LXC ?
I have my PVE system installed on hard disk A, all VM/LXC installed on hard disk B, and backups on smb storage. So when I back up the VM/LXC to smb storage, how much free space is needed on hard disk A for a successful backup?



INFO: starting new backup job: vzdump 119 --storage smb-f --notification-mode auto --remove 0 --node x2 --compress zstd --mode snapshot --notes-template '{{guestname}}'
INFO: filesystem type on dumpdir is 'cifs' -using /var/tmp/vzdumptmp7708_119 for temporary files
INFO: Starting Backup of VM 119 (lxc)
INFO: Backup started at 2025-02-02 13:22:38
INFO: status = running
INFO: CT Name: x2-docker
INFO: including mount point rootfs ('/') in backup
INFO: mode failure - some volumes do not support snapshots
INFO: trying 'suspend' mode instead
INFO: backup mode: suspend
INFO: ionice priority: 7
INFO: CT Name: x2-docker
INFO: including mount point rootfs ('/') in backup
INFO: starting first sync /proc/4187/root/ to /var/tmp/vzdumptmp7708_119
ERROR: rsync: [receiver] write failed on "/var/tmp/vzdumptmp7708_119/data/home-assistant/home-assistant-arm64.tar": No space left on device (28)
ERROR: rsync error: error in file IO (code 11) at receiver.c(380) [receiver=3.2.7]
ERROR: rsync: [sender] write error: Broken pipe (32)
ERROR: Backup of VM 119 failed - command 'rsync --stats -h -X -A --numeric-ids -aH --delete --no-whole-file --sparse --one-file-system --relative '--exclude=/tmp/?*' '--exclude=/var/tmp/?*' '--exclude=/var/run/?*.pid' /proc/4187/root//./ /var/tmp/vzdumptmp7708_119' failed: exit code 11
INFO: Failed at 2025-02-02 13:25:06
INFO: Backup job finished with errors
TASK ERROR: job errors
 
ERROR: rsync: [receiver] write failed on "/var/tmp/vzdumptmp7708_119/data/home-assistant/home-assistant-arm64.tar": No space left on device (28)
It is trying to write that complete .tar to that destination. You need as much free space as your compressed source needs. (Edit: this statement may be wrong...)

Probably you can specify "tmpdir" to point to a location with sufficient space, see: https://pve.proxmox.com/wiki/Backup_and_Restore#vzdump_configuration


Disclaimer: not tested - I do not have this problem...
 
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