[shmoolie]

My Macbook Pro internal hard drive is showing that it's almost full, but when I check the data size of all the files being used I should have an additional 40 GB available. I'm not sure where all this memory has gone.

When I do a get info on my Macintosh HD is shows that the drive has a capacity of 129.48 GB and that there's 127.06 GB on disk.

When I turn on the show sizes option in the Finder and open my Macintosh HD to the first level it shows 4 folders (Applications, Library, System and Users) and shows the totals used in each folder. They only add up to 88 GB.

I'm completely stumped as to where the rest of the 40 GB has gone. I've run disk utility from the command line /sbin/fsck -fy and it frees up a gig or two but that's it.

I never had this problem until last week when I decided to import my old iPhoto photos from my Time Machine backup that was attached to my desktop computer. It imported about 40,000 photos and appeared to fill my hard drive but I still should have those 40 GB.

[Ω]

Download an app called omnidisksweeper. It's free and very easy to use.

[ghporter]

The drive usage you're seeing is actual file size, not disk allocation unit usage. For efficiency, hard drives allocate space in blocks, and these are actually pretty large. Small files like logs tend to take up a lot of space because the file has to use a whole block; HFS+ has a block size of 16kb, so every 1k or 2k log file takes 16k no matter what. That extra space is called "slack," and there is no way to completely eliminate it.

Omnidisksweeper will help you by identifying what files are taking up how much space, which will help you get rid of all the pesky tiny files that are hogging your drive.

[chris v]

Turn off Time Machine temporarily and see if your space comes back. There's an issue with the Finder not seeing some large TM cache files, that will go away with it off. Also, reboot, as you may have a bunch of drive space dedicated to virtual memory, if you've used all available RAM.