Error in Cluster sync after ip change of a node

Mikagltz

New Member
Aug 21, 2025
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Hello everyone,
I’d like to know if someone could help me by answering a few questions.
First, the two nodes are in version 8.4.11. in attach files have a list of descriptions and commands.

After having done this once before, I went through the process again of changing the IP of my second node in a 2-node cluster. Yes, I am aware that having only two nodes is not recommended and that there is a quorum loss when one of them goes down. However, due to company needs, I initially set up the cluster this way.

The issue is that after changing the IP address of my second node for the second time, I couldn’t get the quorum files to synchronize. At least it doesn’t seem to have fully replicated, because on the second node the file at /etc/pve/corosync.conf is still outdated, even though I copied the correct file (as it exists on pve1) to /etc/corosync/corosync.conf.

What I’ve already set up:
  • Both nodes can resolve each other’s names correctly
  • Both can communicate properly, despite being on different networks
  • /etc/hosts is configured correctly on both sides with the right IPs
  • On pve1, both /etc/pve/corosync.conf and /etc/corosync/corosync.conf are correct
  • On pve2, only /etc/corosync/corosync.conf is correct, since I haven’t directly edited /etc/pve/corosync.conf, so it hasn’t replicated yet
After running pvecm updatecerts, everything seemed to freeze — I couldn’t even restart the nodes, and commands like qm list were hanging completely. Since I have many VMs running, here’s what I did on pve1:

systemctl stop corosync
systemctl stop pve-cluster
pmxcfs -l

That allowed me to interact with node1 again (I couldn’t even access its GUI before). After that, I was also able to reboot node2. Since it was already very late, I didn’t make further changes and just left everything running.

My question is:

Based on what I’ve done, what should I do next? Eventually, I plan to rebuild the servers and bring them up without clustering, but for now I need to fix this situation at least enough to back up the VMs — Veeam is currently returning strange errors in this state.
 

Attachments

The issue is that after changing the IP address of my second node for the second time, I couldn’t get the quorum files to synchronize. At least it doesn’t seem to have fully replicated, because on the second node the file at /etc/pve/corosync.conf is still outdated, even though I copied the correct file (as it exists on pve1) to /etc/corosync/corosync.conf.

This is normal, because this work in reverse way.
when you edit /etc/pve/corosync.conf , it's pushed to /etc/corosync/corosync.conf on every node (and corosync is reloaded).

Seem that you have quorum working, you can simply copy manually /etc/corosync/corosync.conf to /etc/pve/corosync.conf (be sure that config_version in /etc/corosync/corosync.conf is bigger than config_version in /etc/pve/corosync/corosync.conf)