Backup (Part III)
As I keep using computers, I keep changing my backup requirements. I’m a fairly simple user: I have one laptop (with three partitions), one desktop (with 3 partitions), and one external hard drive (with one partition) that I need backed up. I back up everything to another external hard drive. I started off with lofty industrial-strength backup ideas. The backup drive had to be on my LAN, always accessible from any computer, and available to anyone on my LAN with a password. (It was a pain to administer and quite slow to transmit data, so I gave that idea up.) I needed industrial strength encryption and versioning. And so on. I even wrote two posts on this: Backup and Backup (Part II).
At first I was using a tool called dar. It had all sorts of features, but its main problem was it used its own data format. This made it very hard to access my archives. Then I switched to Sbackup. This was a bit simpler, but stored the backups in tarred and gzipped files. I thought this would be accessible enough, but when your .tgz file is 60 gigabytes, it’s a major chore to unzip it just to see the contents! I think the rar format solves this problem somewhat. It maintains indexes so that to access the table of contents or to extract any particular file in a rar archive you don’t need to unrar the whole thing. But I think I’ve finally decided that I’m not that interested in compression or encryption or any of that fancy stuff. So I’ve switched to a lightweight tool called rdiff-backup.
rdiff-backup stores an identical copy of a directory on the backup drive. No unzipping, no decrypting; the files are all there for you to see. Every time you run a backup rdiff-backup stores a reverse incremental diff. This means that the backup looks like a mirror of your latest version, but some additional info is stored so you can retrieve an earlier version if you need to. Plus, it’s super easy to use. I just run one small script (for each computer) that basically checks to see whether the backup hdd is connected, then runs rdiff-backup for each directory I want backed up.
Pros: Super-simple, super-fast, has a sort of versioning system, your latest version is immediately accessible.
Cons: Unsecure, takes a lot of space because of no compression, no stable gui frontend for rdiff-backup yet.