I own a MacBook Pro 13 Retina, OSX reports disk usage as 450Gb, but utilities such as DiskInventoryX tells a different story reporting 226Gb as used disk space:

Disk space screenshots

How can I convince OSX to give me back my disk space? Given that DiskInventoryX (and other I tested) cannot find where these 411Gb marked as "Other" are what can I do to identify the issue?

Output of df -h

Device Block Size: 512 Bytes  

/dev/disk1 465Gi 421Gi 43Gi 91%  110450433 11387165 91%  
devfs      184Ki 184Ki 0Bi  100% 638       0        100%
  • possible duplicate of Large difference in reported free disk space – Tetsujin Jan 20 '15 at 12:10
  • the differences I see are much bigger than the size of the backup, that is correctly reported up there. Running "sudo tmutil disablelocal" has no effects at all, even after a cold boot. Finder reports the same wrong size as "About this Mac" – user110375 Jan 20 '15 at 12:46
  • You might be interested in this recent post on OS X daily. – n1000 Jan 20 '15 at 14:15
  • Did you do a disk repair? – n1000 Jan 20 '15 at 14:18
  • yes, no effects – user110375 Jan 20 '15 at 14:27

You may be seeing the difference between used bytes versus used blocks on the disk.

If a tool iterates over the files on your disk and totals the file sizes in bytes, the total value will not match the used disk space.

Try using other disk tools to determine the remaining disk space. The df tool should provide some insight df -h.

Consider using a tool like GrandPerspective to view the contents of your drive; it appears better maintained than Disk Inventory X. Be aware that these tools show file size and not blocks used.

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  • do you think is it possible that the difference causes such a huge difference in disk space report? (200Gb) – user110375 Jan 20 '15 at 13:02
  • In extreme cases it is possible. What does df say? How big is your drive's block size? – Graham Miln Jan 20 '15 at 13:19
  • Device Block Size: 512 Bytes /dev/disk1 465Gi 421Gi 43Gi 91% 110450433 11387165 91% devfs 184Ki 184Ki 0Bi 100% 638 0 100% – user110375 Jan 20 '15 at 13:28
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    Running GrandPerspective from the Terminal / sudo it seems that I have found the root cause of the issue there is a huge file (a Parallels VM) here: /.MobileBackups.trash/Computer/2013-12-11-194848/Volume/Users/mauro/Documents/Windows 8.1.pvm how can I remove it? – user110375 Jan 20 '15 at 14:35
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    Done here: apple.stackexchange.com/questions/168180/… – user110375 Jan 20 '15 at 14:51

After deleting a user account of about 800GB on a new Max OS X 10.10.5 Yosemite system with a 1TB SSD, I was left with only 400GB of free space instead of the expected 900GB.

A whole disk scan of the system by GrandPerspective reported that the scanned files (all of "/" ) were only about 35 GB in size, and that "Miscellaneous used space" was a few hundred GB, which should have been deleted/freed when I killed off the unwanted user account.

I ran Disk Utililty.app to "Erase Free Space" and it churned away creating temporary files to write to the "unused space". While that was running, GrandPerspective reported smaller "Miscellaneous used space" and the Finder reported around 700 GB of free space (up from just a few hundred). Then it jumped to larger "misc used" and smaller "free". Then it reported "running out of room on boot drive!" then it failed with a "cannot create temp file" error, but after I quit Disk Utility.app the finder reported 963GB free space, as did Disk Utility.app as did GrandPerspectives.

So the long and sort of it is that running "Erase Free Space" via Disk Utility.app freed up that free space.

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