[SOLVED] Issues with 2-node Proxmox cluster when one node is powered off

[TheBigZamora]

Hello everyone,

in my homelab I’ve set up a small Proxmox cluster with two nodes. One of them is always running, while the second one I usually keep powered off and wake up via WoL only when needed (to save on electricity).

The problem is that when the second node is down, some things stop working:

PBS backups fail with “Permission Denied”

The VM local console shows “connection timeout”

Is there a way to avoid this behavior? Something similar to VMware’s maintenance mode? Or maybe I’m missing a configuration setting.

Thanks a lot for any advice!

Georgie.

 

[cheiss]

Hi,

I'd first suggest to read a bit into our documentation regarding clusters: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#chapter_pvecm
In any case, with 2-node clusters you always want to have a QDevice: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_corosync_external_vote_support

When one node is powered off, the remaining node only has 50% of the votes needed, but for quorum, more than half are needed, i.e. 51%.
And if the cluster does not have quorum, it will go read-only.

 

[pcarone]

Hi Georgie,

you’re right in a Proxmox cluster, having only 2 nodes is a bit tricky because quorum normally expects a minimum of 3 votes (or 2 plus a QDevice). With just two machines, if one is offline, the cluster can lose quorum, which causes exactly the issues you’re describing.

The command you ran (pvecm expected 1) works as a temporary fix, but it doesn’t survive a reboot. For your setup at home, you can follow apalrd’s guide (or similar approaches) to configure the cluster in a way that avoids quorum issues when one node is down. This essentially allows the remaining node to continue working normally without waiting for the other.

It’s a common scenario in labs, so you’re not doing anything wrong, it’s just the way Proxmox handles clustering.

Hope this helps, and good luck with your homelab!

 

[Johannes S]

Imho you shouldn't have a cluster if you don't want to run the nodes 24/7. For your usecase the ProxmoxDatacenter ( for migration of vms ) is propably better suited

 

[niteshadow]

Hello everyone,

in my homelab I’ve set up a small Proxmox cluster with two nodes. One of them is always running, while the second one I usually keep powered off and wake up via WoL only when needed (to save on electricity).

The problem is that when the second node is down, some things stop working:

PBS backups fail with “Permission Denied”

The VM local console shows “connection timeout”

Is there a way to avoid this behavior? Something similar to VMware’s maintenance mode? Or maybe I’m missing a configuration setting.

Thanks a lot for any advice!

Georgie.

Where is the PBS installed ? Is that a VM ?