About the backup behavior...

[Gilberto Ferreira]

Hi!
I made a backup of vm running Ubuntu, so the backup file has 10GB, the same size of the VM disk, but inside the VM it's using just 2GB.
Is this meaning that it's make a full backup of the entire disk, like, if I have 1 TB in the VM it will create a 1 TB and then make de incremental?
Sorry for the bad English and for silly questions... I am trying to undestand how this wonderful tool works...

Thanks

 

[Gilberto Ferreira]

It's seems to me that it's use the .chunks diretory to store the data... Is that so?

 

[t.lamprecht]

I made a backup of vm running Ubuntu, so the backup file has 10GB, the same size of the VM disk, but inside the VM it's using just 2GB.
Is this meaning that it's make a full backup of the entire disk, like, if I have 1 TB in the VM it will create a 1 TB and then make de incremental?

See the "deduplication" and "incremental backup" features here: https://pbs.proxmox.com/docs/introduction.html#main-features

Effectively, all possible to reuse is reused. If the VM has lot's of zero data it doesn't costs any storage. Same blocks (also between other backups) are also re-used on the backup datastore.

It's seems to me that it's use the .chunks diretory to store the data... Is that so?

Yes, see: https://pbs.proxmox.com/docs/administration-guide.html#file-layout
It's using an efficient content addressable storage (CAS) to store the data.