Distributed Backups

A while back I had a fairly nasty scare – my Linux machine at home went a little funky, and started refusing to mount its hard disks. The timing was pretty bad too, as I’d just backed up my laptop to it then wiped everything off the laptop. After a buying a replacement disk, getting no joy and replacing other bits and pieces, I found I had a defective motherboard on the box. By this time I’d decided to use my spanky new disk as primary, then backup everything to my older, smaller (but not actually broken) 80 gig disk. Sod’s law being what it was, the new drive actually went tits-up with real drive errors, leaving me recovering what I could from it and generally ending up with a mess of files everywhere. This kind of thing could drive a man to actually back things up properly…

In thinking about what I actually want to back up, it doesn’t come down to much. I think I’d like to make sure I have most of my working files, email would be nice, and mp3s are huge but I could re-rip them (of course I have all the original CDs). That leaves me with a few gigs of digital photos that I’d really be upset if I lost.

Having a spare hard disk lying around, me and another broadband-enabled buddy hatched a plan – I’d give him a hard disk, he’d stick it in his machine, and voila! Offsite backups. A little rsync over ssh in the wee small hours (or during office hours, just whenever I’m not using the connection) and my photos are safe from disk crashes, theft, and my house burning down. This’ll work between any two people who have the disk space and bandwidth for it. Maybe you set up ADSL for your Mum and just happen to put an extra disk in the box. The main drawback is that with simple rsync, you have to trust the person on the receiving end – the files aren’t encrypted or protected in any way, and doing so naievely would knacker the speedup you get from rsync.

Posted 09:33, 26 Jul 2003.