Hello Stefan
Here:
nano /etc/vzdump.conf
you can set the proxmox internal TEMP, this is where proxmox actually does the “zipping” (=compression) of the backup file.
tmpdir: /tmp
Note: this can be on an additional partition / disk if you’re short of space and do not want to risk reformatting everything.
If not defined, Proxmox will use the target storage for creating the TGZ files, very much slower over eg NFS than locally, besides, you can run out of space…
So it’s better to be defined, and you know there’s space to do your jobs, like the important backups!
My 2 cents
Andy