How is one supposed to backup a proxmox cluster?

[Miktash]

Say you have 10 proxmox nodes and shared storage. And a backup server.
If I configure the proxmox cluster to backup every night at 2am, it'll start backing up from all nodes to this single backup server.
Everything is connected over a 1G network so it makes no sense to have all 10 proxmox nodes do backups at the same time. The backup servers's link will be congested.

So it's better to spread backups over time, but as far as I can tell, there is no way to do that? I can only manually configure the starting time for backups, for each server. But as VM's are migrated, it's impossible to know when a particular proxmox node is finished backing up.

So, how is one supposed to do this?

Are we required to upgrade to 10Gbe?

 

[m.ardito]

Hi
backup is done by vzdump tool, which has the parameter
-bwlimit

and global configuration is stored in /etc/vzdump.conf.

https://pve.proxmox.com/wiki/Vzdump_manual

afaik

(using 1G link instead of 10G will take 10x time, anyway...)

Marco

 

[Miktash]

So if I have 10 nodes I need to set bwlimit to say 90 megabit? So in total 900mbit..
That way, if they all start their backup process, the 1 gigabit link won't get saturated?

 

[m.ardito]

You can use that and/or also use two 1G link bonded (or more) to the storage. And also use different timings.
Or, also, backup locally to the nodes, if you have local space, and then use a script to move them wherever when/how you like it.
Or, also, use more than one backup storage (which could also have more sense)

So, you have many options..
Maybe also a bit of work though...

Marco

 

[Miktash]

Okay, then I want to add more links to the backup server and use LACP. That makes sense...

The problem: the backupserver is located in rack A where a Cisco WS-C3560G-48TS-S switch is installed. The backup server is also used there.
The proxmox servers are located in rack B where a HP 2810-48G switch is used.

I could run multiple cables between both switches and have the switches do LACP, but is that actually a good idea?


Also, some guy on IRC told me that it's actually a bad idea to have the proxmox nodes and backupserver on different switches. He had some explanation about switches and buffering, which I didn't completely understand. He said it's better to have all nodes and backup server connected on the same switch...