VMs shutting down on remaining host when powering off second node in 2-node Proxmox cluster

[Predis]

Hi,

I’m running into a strange issue with a 2-node Proxmox VE cluster, and I’m hoping someone can help point me in the right direction.

Setup​

• Proxmox VE cluster with 2 physical hosts
• No dedicated third quorum device
• VMs are running one host
• Storage is shared (SAN)
• No HA configured intentionally (unless I’m missing something)

Problem​

When I shut down one of the hosts, the other host shuts down its running VMs, even though that node itself remains online.

What I expect:

• Shutting down host A should leave host B running normally with its VMs untouched

What happens instead:

• Host A is shut down
• Host B stays online
• VMs running on host B are powered off automatically

This behavior is reproducible and happens every time one node is taken offline cleanly.

Troubleshooting done so far​

• Verified that I am not explicitly using HA (but I’m not 100% sure if something is implicitly enabled)
• Checked the shutdown order settings on the VMs
• Looked briefly at the logs but haven’t found a clear smoking gun yet

Any guidance, best practices, or similar experiences would be greatly appreciated.

Thanks in advance!

 

[UdoB]

Interesting! Unfortunately I have no idea what happens. Did you install some magic scripts with hidden automatisms?

Take a look into the journal. After the fact by simple using journalctl or live on the still-turned-on node in a terminal, running journalctl -f

 

[aaron]

Do you see shutdown tasks happening or are the guests being off some other way?
Are you migrating some guests to the remaining host before you shut down the other host? Out of memory could be one cause where the OOM killer stops the guests if there is not enough available on the host.