I haven't been able to backup Lr on my computer for a few months because, I think, the pictures folder was too full from saving old backups. However I wasn't concerned because I backup my computer onto a external hard drive through Time Machine as well as through an offsite back up service. I have since lost work because I opened an old backup look for something and when I opened it up the old backup displaced the more current version. Can the my work be recovered from either the external hard drive or the offsite backup service, and if so how would that be done? I use Lr3 if that is relevant.
I initially posted this via e-mail but it didn't come through so I'm posting it via the website:
LR catalogs are supposed to be local and anything on Time Machine or the external service should be a copy. What are you doing where you actually lose the local copy of your current catalog by opening a backup? Are you overwriting your current catalog with a backup copy? The should be a no-no, and is completely under your control if you take the time to rename things so they don’t overwrite each other.