Recently it became apparent that I should migrate my Proxmox setup to a different host. I was running everything on a Dell PowerEdge 710r which, while a great piece of hardware, I was not using to it's fullest extent, and it was more noise and energy than it was worth.
I was averaging about 4% total CPU usage of the 16 cores I had and it made no sense to keep running it when I had some spare parts in my closet.
So I dug out what I needed and only had to run to the store to get a new M.2 drive. I decided to run everything off of just the M.2 and configure backups to go to my NAS via a mounted NFS share though the Promox GUI.
I decided I wasn't going to migrate the Proxmox drive, just the Vm drive which was on an SSD. I had read online that they would be compatible with any future Proxmox version which I thought was great. I was going to set up the latest version of Proxmox (7.0 at the time of writing). My old install was 6.1.
Just to be safe though I set up an NFS share on my NAS to the 6.1 install and ran a full backup of every VM I would be migrating. Once that was done I powered off the old server, assembled all the parts on the new board, and got 7.0 install on it. Setup went smoothly and I could see the web GUI without issue.
I plugged in the SSD drive that my VM's were on into the new host and . . . they did not boot. Turns out that you need a VM config file for Proxmox to recognize that the file is a VM. Go figure. While I could copy all those over that would entail starting the 710 back up again and digging into the system files. I elected to just say whoops and use the handy backups that I had made earlier. They were the most recent versions anyway.
After restoring them all, everything turned on like a charm and I was able to resume operation like normal.
The new system is using an average of 25% CPU on 4 cores. But it's perfectly fine for my needs. Also, because I am using an NVME drive, I have almost zero IO delay now. The system runs much quieter and uses less power. I definitely happy with the change
Key Takeaway: Always make a backup.