Questions regarding proper setup backup

Hi! I manage several bare metal machines which are rented out. I’m working on automating the entire process.

  1. I’d like to know what the best practice would be to backup data from the machines I manage. I’m thinking to add a master user to all machines so I can run a job via SSH to backup the data.

  2. When setting up a machine for a user, should I add their SSH key to MAAS controller first? I’m working on automating the process.

  3. Is MAAS able to setup VM’s with GPU passthrough? The servers contain NVidia quadro’s on Intel Xeon machines.