Thanks to Dan Tull, Adobe Engineer, for making an excellent point… you’re not keeping your backups with the original catalog, right?
Ok, by default, the catalogs are backed up in a ‘backups’ subfolder alongside the original catalog. If you don’t regularly back up that whole drive to a second drive, what will happen when your main drive dies? You’ll have dutifully run Lightroom’s backups – and they’ll be on that dead drive along with the original catalog. That’s not much help!
So what are you going to do? You really need to have a backup system that very regularly backs up your entire hard drive contents to another hard drive (not just another partition) AND you still need to run Lightroom’s backups. Lightroom’s backups are a safety net against catalog corruption, and the hard drive backup protects against hard drive failure. You definitely want both.
If you haven’t got that set up, at least in the meantime set Lightroom’s backup to back up the catalog to another drive, otherwise all your hard work could be gone with that nasty click click click of a dying drive.
So how do you change the backup location? Here’s the instructions from Adobe Lightroom 2 – The Missing FAQ:
How do I change the backup location?
The backup directory is changed in the Back Up Catalog dialog, which appears when a backup is due to run.
If you need to show the Back Up Catalog dialog to change the location when a backup is not normally due, you can run a backup on demand. To do so, go to Catalog Settings > General panel and change the backup frequency temporarily to ‘when Lightroom starts’. Restart Lightroom so that the backup dialog comes up, and then you’ll be able to change the backup location.
Don’t forget to then change it back to your normal backup schedule.