If you’re responsible for one or more Linux servers, (they provide packages for Linux distributions only, but it may be easily ported to other Unixes) you may be interested in the lesser known tool MondoRescue.
It’s essentially nothing more (but it is a lot!) than a front end to several other GPL’ed tools, including BZip, growisofs and busybox. To cut a long story short, it builds a set of CDs, DVDs, USB sticks with a tiny bootable Linux distribution based on your server’s kernel, which can restore parts or all of your filesystem from tarballs on the media. It can also backup to tape drives, NFS mounts or a local filesystem.
It has (imo) a nice, clean ncurses interface; and it’s quick to use. On an AMD K6 clocked at 350MHz, with 60MB free memory, it took just under 6 hours to compress 8.5GB of data down to a single DVD (4.7GB). Doing the backup with an “average” compression took far less time (around an hour), but would have eaten up several DVDs.
You’re presented with a wide variety of options when you boot up the produced rescue media. You can “nuke” the system and start from scratch, or just restore the parts you want. It can handle new disk geometry, and because the entire rescue system is burnt onto the media, (assuming you used CDs, DVDs or USB storage), it’ll work even if the target machine is clean.