Host maintenance (or something)

[otto001]

Hi,

I just have converted my virsh environement to proxmox and I am sure, that I do not understand all the concepts yet.
I have a 24/7 server running (5.4) and a workstation (also 5.4).
My idea was to have a cluster with the server and the workstation so that I can move running VMs to the workstation in case I have to down the server.
This is working fine so far, but the workstation is not running all the time - and this is causing problems (for example, VMs can not run a backup when the workstation is not up).
Is there a possibility to set the workstation in a maintenance mode (or something), so it does not cause errors when it is not up?
In my private setup there is no need for more than one host to be up 24/7...
Thanks in advance and best regards,
Otto

 

[fabian]

you can give the server two votes instead of one, then it will still be quorate even when the work station is powered down. it also means that if you move guests to the work station, and then power off the server, the work station will not be quorate/read-only until the server comes back up.

another solution would be to setup a qdevice on a third device in your local network that runs 24/7 (some users in homelab settings use something like a raspberry pi for this ). than you have three votes in you cluster, and one of the three devices going down leaves the other two still forming a quorum.

 

[otto001]

Thank you for the very clear explanation. As I have serveral raspberry pis up 24/7, I think I will give this a try.
I have just one more question: What does "not quorate/read only" mean exactly in this context? Will the VM still be able to operate?
best regards,
Otto

 

[fabian]

Thank you for the very clear explanation. As I have serveral raspberry pis up 24/7, I think I will give this a try.
I have just one more question: What does "not quorate/read only" mean exactly in this context? Will the VM still be able to operate?
best regards,
Otto

I'd highly recommend reading the cluster chapter of our Admin Guide

Losing quorum has the following consequences:
- pmxcfs (/etc/pve) becomes read-only (no config changes possible)
- starting/stopping/migrating/.. guests is no longer allowed
- if HA is active and quorum is not re-established within 60s, the node will fence itself (see HA chapter for what that means)

already running guests should be unaffected, except for the HA case of course.

 

[otto001]

Perfect! Thanks a lot!