Proxmox IP Change (Cluster)

Changing an IP address of a Proxmox node that is part of a cluster can be a huge headacke waiting to happen. Luckily it's fairly straight forward with the right commands.

Log into each Proxmox node using SSH.

Start off with the Node that you are changing the IP of.

Edit the /etc/network/interface file to include the New IP

nano /etc/network/interfaces

Edit the hosts file

nano /etc/hosts

Now because all nodes in the cluster need to be informed of the new IP. the corosync.conf file also needs to be updated. However the file cannot be updated if Proxmox is running in Cluster mode. For this we need to boot each node up in local mode, edit the file, save and reboot.

On all Nodes

systemctl stop pve-cluster

pmxcfs -l

nano /etc/pve/corosync.conf

change the IP of the nodes

ctrl O

ctrl W

killall pmxcfs

systemctl stop pve-cluster

Do the above on all Node first and then Reboot them all.

reboot

Done