If you use Time Machine to back up your Mac (as all 10.5-equipped workstations on campus do), backups are pretty much automatic. That's fine, right up to the point where TM starts alerting you that your backup drive is full, and it's going to delete older backups. Under normal circumstances, this is a completely worry-free aspect of the software's behavior. It's just removing out-of-date material to make room for current data.
If your drive seems to have filled up unnaturally fast, though, it can be kind of disconcerting. Especially since Time Machine's backup file structure makes it difficult to tell exactly what's eating up all your space. This is where soma-zone's BackupLoupe comes in handy.
BackupLoupe looks very much like the Finder's Column view. Begin by selecting the backup you want to examine (BackupLoupe handles multiple backup drives and multiple partitions with ease). Then wait for BackupLoupe to scan the selected backup. Once it's done, you can see how much space the selected backup occupies.
Then use the columns to look inside individual directories. Look for large files or folders that appear in every backup, and you'll know what to exclude from your backup (using System Preferences > Time Machine > Options. For instance, my Windows XP virtual machine is 33GB, but contains nothing I can't easily replace, so it's excluded from my backup. On the other hand, my 2.25GB Entourage database takes up a lot of space, since it's backed up every hour, but it's not replaceable, so it stays in spite of the room it occupies.
While BackupLoupe doesn't actually solve the problem of cramped backup drives, it's a handy tool for understanding your backups and deciding whether to prune them back, or request/buy a larger backup drive.
BackupLoupe is about $1.40 from soma-zone, with a free demo available for download. The usual disclaimer: This software is not officially supported or sanctioned by ITS.
(h/t MacWorld)
