Last summer I had a hard disk failure scare from which I was able to recover without data loss. Once I got past the event itself, my first step was to set up a backup solution better than the burn-files-to-CD-R-when-convenient solution that I had been employing.
My solution was to use the backup application that ships as part of Windows XP to create a weekly backup of my data files. The backup file itself gets stored on an external hard disk, so I’m protected from hard disk failure though not from fire, theft, or any other event that would cause both disks to fail concurrently. This job seemed to work fine for what I needed. What I didn’t realize until relatively recently, when I decided to defragment the hard drive, is that the default is to append the backup to the previous contents of the file. The net result was that I had created a single 25+ GB and growing file on my hard disk.
I decided to get a little fancier and create four separate backup jobs. Two are for larger files that change relatively infrequently, primarily photos; a full backup monthly and a differential backup weekly. Two are for smaller data files that can change more often (e.g. Office documents); a full backup weekly and a differential backup nightly. To address the continual growth problem, I set the backup to replace rather than append to the file contents. This level of configuration isn’t as easy as it ought to be via the Backup UI, but I was able to make it do what I wanted.
The issue I have now is that I don’t really want append or replace. I don’t want append because I don’t want the file to grow without bounds, but I don’t replace because I want to keep more than one copy of the backed up data around. In theory I could have a problem now where a hard disk failure would prevent the backup from completing successfully, but not until after the previous good backup had been erased. Rather than having to backup to a hard-coded file name, what I really want is a backup tool that generates a unique file name for each backup — based on the date, for example — and keeps the N most recent files around. I’m pretty sure this isn’t supported by the included backup solution, though I might be able to get close with a bit more manual effort.
Of course, what I really really want is an automated backup system that securely backs up my files to a different location over the Internet, but I’m probably not prepared to pay what that costs. Perhaps I can increase the fault tolerance more easily by putting another external hard disk in a completely different part of the house.