I'm even going one step further than just backing up that Mini server. I've got other dedicated servers running Debian GNU/Linux. On those I wrote specialized backup scripts for various installations: DB, mail, web apps, misc. daemons. Those backups get zipped up and put in a secure web accessible folder. When the backup is deployed a mail is written, my Mini receives it and downloads the backup.

And yes, the Mini itself has Timemachine as its backup(;