Over 25 gb of Space Disappeared Here's my problem: over the past couple days I did a really good clean out of my computer and managed to free up several gigabytes of data and was hovering around 233+ gb of free space. 

Then in the last couple of days I noticed my trash file was taking a really long time to empty (I don't know if this is part of the problem but wanted to mention it just in case).

Last night I noticed I was missing quite a lot of space on my drive, it was around 205 gigs now. I discovered I had accidentally set some large torrent files to be on my main drive instead of an external. No matter, I figured! I would just delete them and start them over on the external. But my disk space didn't seem to change. So I rebooted - after all I had recently used Photoshop and that tends to hog a bunch of space and I don't get it back until I reboot.

I rebooted and there was still the same ~205 gb of free space. I was very confused. I was even more confused when I checked "About My Mac" and saw that it was telling me that in actual fact I only had around 90gbs of free space. THE HECK!?

I did notice that my "backups" were surprisingly high - 119gb in fact. This was especially curious since I have a time machine drive (time capsule) thats supposed to be backing up hourly. I did get a message this morning telling me it was full, but isn't it supposed to clear itself out?

Running WhatSize (it's still running by the way) I see that my .MobileBackups folder is a gargantuan 134gb! I thought these were temporary! For when I'm not connected to Time Machine (WHICH I AM!)

What in the hell is going on? How did I magically lose close to 25 gigs? And how the hell do I get it back?
The current version of Time Machine keeps two types of backups.  There are backups that are stored on your computer as well as network backups that are stored on your networked storage (time-capsule, NAS, etc).  You can see these by entering Time Machine and looking at the timeline ticks to the right.  The pink/purple ticks are network copies and the white ticks are the ones on your local computer.  The local backups occur when your network storage is not available, also they may occur more often than the 1hr snapshots set for network backups.  As your hard drive fills up, OS X will start to cut back the amount of space it uses for local backups.  If you want to disable this feature and recover your local disk space, then open a terminal (Applications -> Utilities -> Terminal) and enter the following command followed by your password.

sudo tmutil disablelocal


This should turn off the feature and free up the space.  You can turn it back on with

sudo tmutil enablelocal