[pbs-devel] Poor client backup performance [Bug#3811]

[Lubomir Apostolov]

Hello,

One year ago I talked about this here without success.

Proxmox Backup has no differential read algorithm and no plans to do it. It handles only changes during current backup, but has to read every time all backup data. If you have 20Tb to backup every 3 hours, your storage must be able to read at at least 2Gb/s 24/7 and even more if you dare use your VMs at the same time. Complete design failure except for some dev/lab setups.

It could use snapshots from the underlying storage like ZFS or Ceph, but no, devs seem happy without it. A simple script for differential snapshot copy does a better job.

Best regards,
Lubomir


-------- Message d'origine --------
De : Mark Schouten <mark at tuxis.nl>
Date : 30/12/2021 10:07 (GMT+01:00)
À : pbs-devel <pbs-devel at lists.proxmox.com>
Objet : [pbs-devel] Poor client backup performance [Bug#3811]

Hi!

I switched a few servers to Proxmox Backup Server this week (a slow week :)), but am somewhat disappointed in the performance of the client. I created bug 3811 for it, and would like to help and assist in debugging this issue.

The mentioned server in the bug should backup about three times per day. Currently, the machine is working on it almost fulltime, because the backup takes more than 7 hours.

I think the client reads all files I every run, and I would expect stat’ing the files should be enough to determine whether a file should be re-read, but I’ve not spent a single second reading the code, so I do not have any more than suspicions.

As said, I’d like to help improving this situation, please let me know what you need from us.

https://bugzilla.proxmox.com/show_bug.cgi?id=3811

Kind regards,

—
Mark Schouten, CTO
Tuxis B.V.
mark at tuxis.nl<mailto:mark at tuxis.nl>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.proxmox.com/pipermail/pbs-devel/attachments/20211230/7c0f235f/attachment.htm>