Erase Free Space frozen

Discussion in 'OS X Mavericks (10.9)' started by bennyprofane42, Jun 2, 2016.

  1. bennyprofane42 macrumors newbie

    Joined:
    Jun 2, 2016
    #1
    So I'm using the Disk Utility to erase free space on my Macbook (running Mavericks). I had 77GB available on my 750GB drive before I started this. It got about 80% through (using the 3-pass version) and then seemingly froze on "creating secondary temp file"--and my available space had plummeted to 8GB. Because it wasn't doing anything I chose "Skip," but now it's frozen on "Skipping" (at least an hour now), with an ugly warning as to why I can't quit Disk Utility.


    How do I get it to stop?

    Is this just something where I have to wait a day or so?

    How can I erase free space if it eats up all my free space in erasing it (which, of course, makes no sense)?
     
  2. grahamperrin macrumors 601

    grahamperrin

    Joined:
    Jun 8, 2007
    #2
    There's sense.

    Loosely speaking, a sequence of logical actions cause all free space to be overwritten in a way that suits your preferred routine for secure erase.

    Use the Force Quit dialogue. Has Disk Utility stopped responding?
     
  3. bennyprofane42 thread starter macrumors newbie

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    Jun 2, 2016
    #3
    It finally stopped. I tried it again using the single-pass version and got the "can't create temporary file" error.

    If "deleting" files actually, you know, deleted the files, this wouldn't be an issue.
     
  4. grahamperrin, Jun 2, 2016
    Last edited: Jun 2, 2016

    grahamperrin macrumors 601

    grahamperrin

    Joined:
    Jun 8, 2007
    #4
    That's vaguely familiar, I can't recall whether it's a bug. An excuse for me to boot El Capitan and see how it behaves.

    If you use Disk Utility in Mavericks to verify the volume, is the volume apparently OK?

    If overwriting was the default, the OS could become unexpectedly slow.

    Do you ever use Secure Empty Trash? Or FileVault 2?
     
  5. JohnDS macrumors 65816

    Joined:
    Oct 25, 2015
    #5
    You don't have enough free space for the temporary files the Mac needs. You should never let your free space get below 15%. Archive and delete some files and don't forget to empty the trash. Then try again.
     
  6. grahamperrin macrumors 601

    grahamperrin

    Joined:
    Jun 8, 2007
    #6
    That's not applicable to Apple's Erase Free Space routines.
     
  7. JohnDS macrumors 65816

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    Oct 25, 2015
    #7
    OP said "t got about 80% through (using the 3-pass version) and then seemingly froze on "creating secondary temp file"--and my available space had plummeted to 8GB."
     
  8. grahamperrin macrumors 601

    grahamperrin

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    Jun 8, 2007
    #8
    It's normal for free space to drop to close to zero.
     
  9. bennyprofane42 thread starter macrumors newbie

    Joined:
    Jun 2, 2016
    #9
    I just let it spin and spin and spin and finally, after about 15 - 20 minutes it stopped with a fail message. However, I suddenly had 4GB more free space. So apparently it works even though it tells you otherwise.
     
  10. grahamperrin macrumors 601

    grahamperrin

    Joined:
    Jun 8, 2007
    #10
    Yep.

    As far as I recall, in at least one secure erase procedure there's use of a sparse bundle disk image. I assume that the bands within the bundle are the default size (8 MB).

    During the procedure, the conventional wisdom of maintaining a percentage (or amount) of free space becomes … somewhat negligible. As the bands are reasonably large, there's a low risk of growth/fragmentation of the B-trees. A bundle of as many bands as is appropriate and then then the OS can suddenly handle the disk image; suddenly remove all directory entries for all bands and other temporary files that were used to securely overwrite the free space.
     

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