I am hosting PBS under PVE. Should I install Guest Agent manually?

[PythonTrader]

I installed PBS using its ISO on my main PVE.

I was expecting that PBS installation ISO comes with Guest Agent, but apparently it doesn't:



Should install the guest agent manually?

 

[Dunuin]

Should install the guest agent manually?

If you care about consistent backups, yes.

 

[PythonTrader]

If you care about consistent backups, yes.

Thank you for help.

Is there any circumstance that the guest agents should NOT be installed on a PBS VM?

 

[Dunuin]

Installing it is nearly always best practice. There are very rare cases (I think some DBs on Windows) where the fsfreeze might be problematic but I don't see anything that could be problematic with PBS.

 

[PythonTrader]

Installing it is nearly always best practice. There are very rare cases (I think some DBs on Windows) where the fsfreeze might be problematic but I don't see anything that could be problematic with PBS.

Thank you @Dunuin . I am new here and you helped me a lot. Appreciate it.

 

[Pavel Tide]

@Dunuin ,

Would you elaborate please?

How does presence/absence of the guest agent on PBS server affect consistency of the backups? I assumed that the guest agent has to be installed inside VMs that are getting backed up.

Thanks!

 

[santiagobiali]

@Dunuin ,

Would you elaborate please?

How does presence/absence of the guest agent on PBS server affect consistency of the backups? I assumed that the guest agent has to be installed inside VMs that are getting backed up.

Thanks!

If your VM hosts a database, it used to cause problems. Now it can be remediated.

More info:
- https://pve.proxmox.com/wiki/VM_Backup_Consistency
- https://blog.datact.ch/backup-mssql-server-with-proxmox

And this post, but it's outdated: https://forum.proxmox.com/threads/p...sql-backups-backups-without-fs-freeze.111526/

 

[Pavel Tide]

That is:

- it is not required to install the in-guest agent onto the PBS server
- in-guest agent should be installed only onto the VM that you back up

Thank you

 

[PwrBank]

If you care about consistent backups, yes.

I guess in this case, why would you be using PBS to backup PBS?

 

[tcabernoch]

I see some debate on this issue.
Let's make it 100% clear.

Yes.
If you are running your PBS as a PVE guest VM ...
Yes, you should install qemu-guest-agent.

 

[Pavel Tide]

Thank you the response. However, it's still not clear what purpose does qemu-guest-agent serve in this case.

Based on this article it seems that in case with PBS it will only serve time sync (unless someone is also taking snapshots of the PBS server itself).
I doubt that absence/presence of the agent on PBS server in any way affects the consistency of backups of other VMs (as it's been claimed above).

Please elaborate.

Thanks!

 

[tcabernoch]

Alright. It's not that anybody wants to debate this.

We install the virtual drivers in the VMs because that, in general, is the way to avoid headaches.
It displays IP information in the PVE interface if you've configured the guest agent.
And if you tell it to shut down, it actually does so instead of just hanging.

As for the stun/timesync, well ya. It supports that. And memory ballooning.
These are basic features of a virtual machine. They should work.