Need help...PVE8.3 upgrade to PVE8.4

[8930851]

I have a PVE 8.3 cluster with 3 nodes ( dell R450 ), using pveceph for storage.

Recently one node was down( hardware issue) ,then I recovered the system and wanted to re-install the PVE8.3 but I don't find PVE8.3 ISO on the website. I just download a PVE8.4 ISO and installed.

Now the new PVE8.4 node is running correctly with no cluster.But my VMs are still running on the old PVE8.3(only 2 nodes) cluster.

I want to combine the PVE8.4 node and the 2 PVE8.3 nodes into a full PVE8.4 cluster of 3 nodes. How Can I do? I need some advices such as steps to do it safely.
Thanks!

 

[leesteken]

You should update each node: https://pve.proxmox.com/pve-docs-8/pve-admin-guide.html#system_software_updates . And you most likely need to reboot each node.
Updating to an up-to-date PVE 9.x, since PVE 8 will be out of support soon, is more involved: https://pve.proxmox.com/wiki/Upgrade_from_8_to_9