Changing the host name of a Proxmox node is unfortunately a bit harder than changing the hostname of your typical Linux machine. This article will guide you through the process. Keep in mind that this only covers changing the host name for a standalone node, I don’t know if the process is different when the node is part of a cluster.
First change the host name like you would do on any Debian based machine.
hostnamectl set-hostname NEW-HOSTNAME
Update your hosts file with your favorite text editor.
Proxmox should momentarily create a new node with the new host name. You can see this here.
ls -la /etc/pve/nodes
There you will find a folder with the same name as your old host name and one with your new host name. If you can’t see the folder with your new host name you might have to wait a bit or you can restart the machine.
Now I like to take a backup of the current config files just in case:
cp -r /etc/pve/nodes/OLD-HOSTNAME /root/
Next you need to copy the configuration files for the old host name to the new one. I had some problems doing this, not sure why, so I copied mine from the backup which worked.
cp /root/OLD-HOSTNAME/qemu-server/* /etc/pve/nodes/NEW-HOSTNAME/qemu-server
Now reboot the machine.
This should be everything you have to do. I had one problem though, none of my VMs would boot. Yes that is a pretty big problem but it was because they couldn’t find my LVM-volume. The problem was in
lvmthin: data thinpool data vgname pve2 content rootdir,images nodes OLD-HOSTNAME
I just had to
nodes to the new host name and it worked.