Proxmox Backup Server: Space Needed

[FormerVMW]

Hello,

I'm hoping someone who has deployed a PBS, and has good data on their prior backups via PVE, can provide some input.

The current size of my dump directory is 4.6T of compressed backups. The size of the VMs on the LVM-THIN mount is ~13TB (actually used). My dump directory contains 1 full backup for each VM I have deployed.

With PBS I would be using dedupe and intend on doing daily incremental backups with a week retention. The data change rate is minimal so daily backups shouldn't produce a large amount of changed blocks.

Considering the above information, how much space do I need when initially deploying PBS?

 

[mgabriel]

If your prior backups use zstd for compression, you should calculate about the same for the first backup on the pbs. Each subsequent backup can then be deduped and only needs to store additional chunks. If you have multiple VMs with the same chunks, dedup can even be applied on the first backup as deduplication is done on a per-datastore-basis, but I would not count on it.

So I'd assume to provide at least ~4.6T+ of space for the first run.

 

[FormerVMW]

If anyone finds this thread in the future, here are the results:

4.6T zstd compressed backups via the standard Proxmox vzdump backups became 5.27T of used space on Proxmox Backup Server.

Additional space used by subsequent backups, after the initial backups, is minimal. Our Deduplication Factor is 6.08.

YMMV, but the above is based on our real world experience.

 

[mgabriel]

Thanks for the update. The 5.27TB value comes from the dashboard or any command from the cli? It may be different depending on the filesystem/storage below, that's why I'm asking.

 

[FormerVMW]

That's a good question.
df: /dev/sda4 11T 4.9T 6.0T 46% /pbs-storage

Dashboard:

 

[FormerVMW]

PBS has now been live for over a month and backups are now purging off based upon our retention schedule. I figured I would post some updated disk usage. 10% of our backups are daily (Monday-Friday) backups with a 10 backup retention (two weeks essentially) and the other 90% are weekly with a 4 backup retention (one month retention).



Very impressed with PBS and I highly recommend it to anyone... Especially those still solely using the included vzdump (full) backups of PVE itself.