Setup lake2 node for ceph storage

The lake2 machine will hold 7.2 TiB of disk space used for the CEPH filesystem. To install NixOS:

• Enable serial in GRUB
• Reboot and get a serial console
• Boot NixOS with kexec
• Perform the installation
• Add NixOS entry to GRUB
• Configure the disks for ceph
• Set default boot entry to NixOS
• Do some benchmarks