gnt-dal cluster ganeti setup and burn-in

as per TPA-RFC-43, once we have contact at the new colo (#40967 (closed)), the servers are ordered and shipped (#40966 (closed)), burnt-in (#40969 (closed)), and installed (#40970 (closed)), we need to setup Ganeti on the new nodes.

1. disk partitionning (RAID, LUKS, LVM...)
2. install first node
3. Ganeti cluster initialization
4. install second node
5. confirm DRBD networking and live migrations are operational
6. VM migration "wet run" (try to migrate one VM from cymru and confirm it works)

once this is done, the cluster is operational and ready to accept VM migrations (#40972 (closed))