Upgrade Proxmox via soft migration

[copymaster]

Hi!
We are using a 5 node proxmox 4.2 cluster with several VM's.
Now i want to upgrade to proxmox 5 and read in the wiki that it should be possible to ADD a Proxmox 5 node to the existing Proxmox 4.2 cluster.

I just want to make sure i am right with my view of the procedure.
Plan is as follows:

I have a brand new physical Server which is installes with Proxmox 5. Network and DNS is working.
There are NO vm's on that server now. Can i just add this Server to the Proxmox 4.2 cluster??!

I hope to add it, then migrate some VM's to that server so that the next physical Server gets "free". Then i would remove that Server from the cluster, power it down and install PROXMOX 5 on it. Afterwards i would add this Server to the Cluster again to migrate the next vm's and so on. At the end i hope to have a working Proxmox5 cluster.

Can someone please tell me if this could work?
And by the way: I have NFS shares on every physical server actually. i would unconfigure that shares before removing the proxmox4 servers from cluster.

Thank you

 

[Alwin]

While it should work to add a PVE 5.x node to a 4.x cluster, it is good to run with the latest 4.x on the cluster first.You can test the procedure on a virtual cluster.

You can also in-place upgrade your nodes, as you move away all VM/CT.
https://pve.proxmox.com/wiki/Upgrade_from_4.x_to_5.0

As always, have a backup for just in case.