Migrating to new server

Prepare by lowering DNS TTL for your domains (matrix.DOMAIN, etc.), so that DNS record changes (step 4 below) would happen faster, leading ot less downtime
Stop all services on the old server and make sure they won’t be starting again. Execute this on the old server: systemctl disable --now matrix*
Copy directory /matrix from the old server to the new server. Make sure to preserve ownership and permissions (use cp -p or rsync -ar)!
Make sure your DNS records are adjusted to point to the new server’s IP address
Remove old server from the inventory/hosts file and add new server.
Run ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,start. This will create the matrix user and group and start all services on the new server