157gb of my 159gb mac is showing as used. In the storage area 145gb of this is showing as other. What can this be? I have just downloaded whatsize app to understand and whilst the 157gb is showing as used on hard drive when you click into the detail within whatsize it does not add up to anywhere near this. About 20gb is broken down in the detail. Would really appreciate some help as I'm at a loss I have not been able to use my mac properly for months now and when I took it to a computer repair shop they tried an omnisweeper but this made no difference.

  • OmniDiskSweeper will show where the space is taken up but will not clear space for you - what did it show took up the space? – user151019 Mar 29 '13 at 17:45

Is this a MacBook? I ran into something similar and it turned out to be the local Time Machine snapshots. This was a new feature in OS X 10.7 Lion. Some programs show that space as used and some don't. Finder doesn't show that space as used but Disk Utility does.

Make sure to run WhatSize in "As Admin" mode to get an accurate representation of your disk usage. This isn't available in the App Store version. In that mode it will show you the local Time Machine snapshots.

Here is more information about local snapshots.

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  • Or one of the free alternatives like GrandPerspective or DiskInventoryX – user588 Mar 27 '13 at 23:55
  • Yes it's a macbook thanks very much for the advice i'll try this now – Karen Mar 28 '13 at 10:11
  • OK so i've used DiskInventoryX which does break things down for me thank you, very useful. E.g. it is showing me that a lot of space has been used up in photos (42gb - I have 7500 photos saved so I'm assuming that makes sense??). I notice that 16gb has been used against ipod photo cache. Any ideas what this is and if I need to keep it please? – Karen Mar 28 '13 at 10:55
  • Generally, anything that says "cache" is safe to delete. That's temporary storage that applications use to save time. Of course, make sure you have a current backup before deleting things you're unsure of. 42Gb for 7500 photos isn't unreasonable. That's about 5.6Mb per photo. When you edit a photo in iPhoto it keeps the original plus the modified version. – SSteve Mar 28 '13 at 14:54
  • Thanks so much I have now freed up nearly 20gb already. Really appreciate your help and advice. – Karen Mar 28 '13 at 15:39

If you're comfortable in the terminal (Applications->Utilities->Terminal) run the following command

sudo du -x -k / | sort -n 

This will ask you for your password then it will list all the directories with the size of that directory (and all subdirectories under it) in order of size. From this output you can sort through where your space is being used.

If you're not so comfortable there I've used Disk Inventory X in the past; not sure if


You can see what it's output looks like at


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  • How does this show anything different to OmniDiskSweeper which the questioner has run? – user151019 Mar 29 '13 at 17:48

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