- install new servers at new location of same or similar model as the old servers, and load them with a basic CentOS install
- rsync oldserver:/ to newserver:/ including customer files
- reboot new server and fix whatever goes wrong (MAC addresses changing, etc)
- move BGP announcement of hosting IP range to new colo
- shut down and remove old servers
The actual process is more complicated. During step 2, I hit a problem with cPanel’s /home/virtfs directory tree.