I went with the always on Mac mini as a server. Most recent update is described here: Updating my Mac mini server setup
Pertinent to this thread:
- Backblaze account only backs up the server.
- Server holds Time Machine backups for other systems. These are not backed up to Backblaze.
- Chronosync/Chronoagent used to do daily backups of data on other systems to the server. Backblaze then backs these up.
- Drive “toaster” used to clone server drives to bare drives that are kept offsite. Two sets of offset drives are swapped.
This means that data on the “work” computers, two iMacs and a MacBook Pro, are backed up to two places on the server, to Backblaze, and alternating offsite drives. None of the “work” computers have external drives.