Understanding VZDUMP backup routine, size of backup, etc...

[arretx]

Okay, so I'm wondering about how the backup works regarding it size. My Ubuntu VM has about 70GB of actual data, but the LVM defined in Ubuntu is 150GB. Normally I would use the backup/restore feature in Webmin inside of the VM to backup the important data, but it seems so much simpler to just take a snapshot of the VM as a system backup.

If I SSH into Proxmox, then change to a storage location for dumps (/mnt/systemBackups), and then run `vzdump 100`, there's a line in the backup shown as:

INFO: include disk 'scsi0' 'local-lvm:vm-100-disk-0' 150G

Is the backup actually going to create a 150GB file, or is the backup going to be the size of the data in the VM?

 

[Dunuin]

The backup will contain the full 150GB but if you use LZ4 or ZSTD compression the unused space should be very good compressible, so it should be similar in size to your actual data.