Is Erase and Install a Safe Choice ??

Discussion in 'macOS' started by fab5freddy, May 25, 2009.

  1. fab5freddy macrumors 65816

    fab5freddy

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    #1
    I am about to sell my mac pro Tower and
    am going to do an Erase and Install of OS X Leopard....

    Is the erase pretty safe in terms of deleting all my sensitive data ?

    I mean , is it safer to do an erase first , then install ??

    Thanks ! FF
     
  2. spinnerlys Guest

    spinnerlys

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    #2
    The data will still be recoverable after a "simple" erase and install.

    You could do a Secure Erase while you're in the installation process with the help of Disk Utility.

    [​IMG]
    from http://www.ehow.com/how_4815466_os-x-hard-disc-volume.html



    To get into Disk Utility while booted from the installation DVDs:

    Insert the Mac OS X Install disc that came with your computer,
    then restart the computer while holding the C key.

    When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu. (In Mac OS X 10.4 or later, you must select your language first.)

    Important: Do not click Continue in the first screen of the Installer.

    If you do, you must restart from the disc again to access Disk Utility.



    from http://support.apple.com/kb/TS1417
     
  3. fab5freddy thread starter macrumors 65816

    fab5freddy

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  4. xraydoc macrumors demi-god

    xraydoc

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    #4
    7-pass and 35-pass will take a LONG time, by the way. If you're that security-conscious (if it even helps), be prepared for it to take a long time to finish (5+ hours for high-capacity hard drives).
     
  5. fab5freddy thread starter macrumors 65816

    fab5freddy

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    #5
    How long does Zero Out Data take with a 300 GB Harddrive ?
     
  6. fab5freddy thread starter macrumors 65816

    fab5freddy

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    #6
    It's Strange. Zero Out Erase took 2 hours for a 300 GB drive !

    Is that normal ?
     
  7. DarkJaye macrumors member

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    May 11, 2009
    #7
    The poster above was talking about the 7-pass and 35-pass options taking a long time, the normal zero out erase is the quickest secure option.

    If you had picked the 7-pass erase, it would've have taken you 7 times longer to erase the data, because it essentially overwrites the drive with 0's 7 times, instead of just once.

    I'm personally not that paranoid (and don't have data that I consider to be sensitive enough for a 7-pass erase) so a single zero out erase is fine for me.
     
  8. Jethryn Freyman macrumors 68020

    Jethryn Freyman

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    #8
    Yes.

    I'd recommend a 7 pass erase though, if you really do have sensitive information there.

    If someone is likely to be willing to use a magnetic force microscope to try to recover your data, you need a 7 pass erase.
     
  9. xraydoc macrumors demi-god

    xraydoc

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    #9
    Exactly. For most people, this is not a likely scenario. This is why single zero pass is sufficient for most.
     
  10. Imola Ghost macrumors 65816

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    #10
    I was going to zero out a hard drive that I sold and I chose the 7 pass. When it was finally done calculating the time, it was like 2 days!

    This was on a 500gb hard drive.
     
  11. fab5freddy thread starter macrumors 65816

    fab5freddy

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  12. spinnerlys Guest

    spinnerlys

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    #12
    You have to consider, that with a 7-Pass Erase, 465GB (on a 500GB drive - which is 465GB in reality, or 500.000.000.000 bytes) will be written seven times onto the HDD. That's 3.18TB in 48 hours with a write speed of 19.3MB/s, which should be USB 2.

    465GB * 7 writes / 48 hrs / 60 min / 60 sec * 1024 (factor for getting from GB to MB) = 19.288888
     

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