I am up to my waste (sic) in old XP computers that I have replaced with newer units since the end of XP support.
So I built a backup server with some salvaged Dell Dimensions and a surplus hot swap cradle I had in the shop.
I ended up with a P4 with 1GB RAM and 3 x 320GB HDD's numbered 1, 2, &3.
I used xUbuntu to set up a system that boots, connects to the network shares on the main server, then rsync's the shares to the local hard drive. After it finishes, it powers it's self off.
I then cloned the system to the other two drives, so they are essentially the same drive.
I installed it as a trial in a clients office.
Before going home, the office manager removes the drive and puts the next one in sequence in the machine.
He then power's it up and walks away.
The previous drive goes into a little carry box and gets put in the fireproof safe.
They love it!
1. It's a "turn it on and walk away" solution. No other user intervention needed.
2. It is only connected to the network while it is backing up. If a workstation get's infected during the day, it will not have access to the backup. So many times have I walked into an office and seen the backup drive sitting connected to the network.
3. It was cheap! The hot swap bay was only $25, and the rest was made from parts that were destined for the e-recycle!
4. It is simple to maintain. You can boot from a live cd and check the drives and logs to make sure it is working.
5. It is (almost) bullet proof! The ip is blocked by the router, so it cannot get out of the local network. It has no open shares of it's own, and no one can get in, except in local mode!