Jeremy Zawodny has some interesting calculations on the absolute cost advantage of using S3 for your home backup server. For me however the most compelling argument is later in his posting when he mentions the administrative cost of running a highly available home server.

I recently lost 2 disks in my home raid setup rendering the 1 TB data store useless. It looked like a controller failure that corrupted the disks and the response of the vendor was it was my own fault as I hadn’t kept track of the firmware releases for the controller. One moment you are thinking you have great home setup, next moment you are in deep trouble. All because you didn’t subscribe to all the bulletins for the different components in your server. There is just too much to do in administrating your own servers to guarantee that they actually have the reliability you need.

My backups into S3 are of those files that would seriously affect our personal life if we would permanently lose them: address books, emails, letters, family photos, etc. Jeremy’s posting touches on that it is actually cheaper to do this with S3 but I would have done this even if it was more expensive given that it is just not worth the headache worrying about when your home server will fail next…