Let me start off by saying that I didn’t come up with this backup mnemonic, rather Peter Krogh first wrote this up (to my knowledge) in this blog post.
As I recently re-learned, backups even done right are hard to do well. In my case there’s a chance that I still would have lost my data, but there’s no accounting for human error in every case.
The “Three, Two, One” backup strategy is pretty simple:
- Three – A file isn’t backed up until there are at least three copies of it, the original and two other copies not on that machine.
- Two – The backups must be on two different media types. For example, a hard drive and a DVD drive, or a tape backup.
- One – Finally, one of those copies should be stored off-site or at least off-line. A cloud storage service such as Carbonite, Amazon Cloud Drive, Google Drive, or even storing it at a friends house.
In my case (backing up my website), one version would have been the site itself, a second would have been a copy stored on my home computer, and a third would have been stored on a DVD (probably not every month, but probably once every six months or so) or I would have copied it up to my Google Drive.
Sadly, I didn’t take those precautions and now I’m paying the price (thankfully a small one).
And I’ll add one more thing – be sure to VERIFY the backup you created periodically. It does you no good if the restore process fails or isn’t documented for someone else to perform.