A backup guide for the rest of us

On his blog Tim Bray recently offered some advice on protecting your data - it’s backup advice for the rest of us:

Note that these are not rules for professionally-managed data centers, who have incredibly complicated backup requirements and often live in a regulated environment. If you’re a pro, the only way to be safe is to hire an expert and throw some real money at the problem.

This advice is aimed at the users of personal computers, whose needs are simpler and less variable.

Essentially his four rules are:

  1. Don’t use proprietary file formats.
  2. Don’t erase anything.
  3. Store everything twice.
  4. Do occasional ad-hoc and regular full backups.

Make sure you read his article to get the full explanation on these.

I reckon his most important one is number 2, which encompasses the idea that the biggest danger to the integrity of data on a computer system is the user him/herself. Couple that with this insight:

The cost of disk space these days is just so ridiculously low that most people never manage to fill up their laptops. So why on earth would you invest your precious time in a dangerous activity (deleting things) in order to conserve a resource that’s essentially free?

And you realise he’s right. We’ve been used to thinking that storage is expensive whereas on a per megabyte basis it’s never been cheaper. And what’s the real cost of trying to recover or (worse) reconstruct a thoughtlessly deleted file?

My workhorse computer is a relatively new notebook and it holds disk images from two previous machines - generally just accumulated “stuff”. But there have been several times - including one just yesterday - when I’ve needed to delve into the old collection to find a file that I wouldn’t have expected to need again.

I reckon the only thing I’d add to Tim’s advice is a coda to number 3: sometimes make a third copy and store it somewhere else. Sure if your house burns down the contents of your hard drive isn’t going to be your first priority, but at some point it will become a priority and if you’ve got a fairly recent backup somewhere else it’ll make the recovery effort a little less painful.

Right, now if you’ll excuse me I’ve got to go and buy another USB external drive…