I use a backup program of my own devising to copy the whole of my server to the external disk drive. It's not a full system backup, because some of the interesting files are locked. It couldn't be used for a system restore, for example. It includes all of the home directories from the server, all of the photos, movies and music, and anything else that isn't locked at the time.

I'm not too bothered if I lose the entire PC -- I'll just reinstall from scratch anyway. I am bothered if I lose the photos, etc., since SWMBO will not be amused.

My website is hosted on a VPS, which is backed up by my hosting company, but I use rdiff-backup to bring it all back to (a Linux VM on) my server once a day as well.