I’m a fan of Time Machine. Actually I’m a fan of backing up data in general. Some might even say that I’m paranoid because of the number of different backup methods that I employ. Not only do I use Time Machine but I also do clone backups using SuperDuper! and backups to the cloud (offsite) using CrashPlan. Recently I realized that I hadn’t updated my clone backup that I carry with me as a safety precaution in case I have a hard drive failure while on the road, in a while. I plugged in my portable drive and began the SuperDuper! clone. However, SuperDuper! error’d out and when I checked the log it seemed that it was having an issue backing up something called “.Mobile Backup”. It was actually reporting that there wasn’t enough room to back this folder up, which I knew wasn’t right because the backup drive and the internal volume were the same size and therefore everything should fit. I began to wonder what this hidden folder was and after doing a little research I discovered that Mac OS X 10.7 Lion has implemented a local Time Machine snapshot! The purpose of this is for MacBook/MacBook Pro users who may be away from their regular backups for a while (traveling) to have a safety net for accidentally deleted files (not drive failures). It makes sense and it’s a nice thing that Apple is doing for us. However, not only was this folder screwing with SuperDuper!, it was also chewing up about 20GB’s of space. Now in fairness, Time Machine will not let it eat up all your internal hard drive space (as it does with an external drive) and will automatically shave off backups if you get low on space and even stop doing local backups if necessary. However, I’d rather have my 20GBs instead of the safety net.
Luckily there’s a Terminal Command to Disable it:
Just launch the Terminal App and enter sudo tmutil disablelocal (if you ever want to enable it again just do: sudo tmutil enablelocal) After I disabled it I immediately gained 20+GBs of space back and my SuperDuper! clone worked as usual. Hopefully the guys at Shirt-Pocket software will fix SuperDuper! to work with this folder, but in the meantime I’m going to leave this feature off.