Project: Automated offsite backups for an NSLU2 – part 2

11 November 2006

Previously in this series: Part 1.

In the last post, I explained that I was going to work out some way of getting an NSLU2 backed up to some kind of offsite data storage without any intervention from a fully-fledged computer.

Let’s look at the easy bit first; how do I get some cheap storage online? Sadly, Google has yet to announce its 100Gb free GDrive, so for now I’m going to assume that I will use the Amazon Simple Storage Service, widely known as S3; this is cheap – from their webpage,

  • Pay only for what you use. There is no minimum fee, and no start-up cost.
  • $0.15 per GB-Month of storage used.
  • $0.20 per GB of data transferred.

It’s also meant to be highly reliable; Amazon use it themselves internally, so presumably it’s at least good enough to store the mission-critical data of a multi-billion dollar business. My data will probably be safe enough.

So that’s the storage – next, how do I get it there? This is likely to be harder. Although – as I noted in my first post in this series – the NSLU2 has an automated backup feature, it’s really designed to allow the device to back itself up to a drive shared by another machine on the same LAN, or to allow it to back up directories shared by other machines. Useful for protecting yourself against disk failure, useless for protecting against burglars.

So, getting this working will require getting the NSLU2 to do something it was never designed for. This would be a daunting task, but conveniently, the NSLU2 uses a cut-down version of Linux – and while the manufacturer does not support any kind of modification, a few Google searches suggest that there’s an active community of people devoted to hacking it into doing things it’s not designed for.

I can now refine the aims of this project; initially I wanted to get an NSLU2 to back itself up to some offsite system. I now know that I want to somehow persuade the NSLU2 to run non-standard software that synchronises its contents with Amazon S3.

Next: Hacking the NSLU2