Selling MBP - How to delete private files

Discussion in 'Mac Basics and Help' started by tmpmb, Aug 5, 2009.

  1. tmpmb macrumors newbie

    Jan 31, 2007

    I'm selling my old MBP and I was wondering what's the best method to insure that all my private files are deleted.

    I have done some research and found out about the Mac "Disk Utility erase"

    Also I plan on doing a fresh install of the OS right after the "Disk Utility erase"

    Is this enough? Any tips and advice?

    Thanks :)
  2. thegoldenmackid macrumors 604


    Dec 29, 2006
    dallas, texas
    The long version of erase and install does seven (correct me if I'm wrong) erases and then the install?
  3. tmpmb thread starter macrumors newbie

    Jan 31, 2007
    Thanks for the quick reply.

    Yes you can either choose between 7-Pass erase or 35-day erase. I plan on doing the 7-pass erase and then do the fresh install?

  4. KingYaba macrumors 68040


    Aug 7, 2005
    Up the irons
    35 is freakin' overkill. I'll bet one pass is sufficient.
  5. lee.anderson macrumors regular


    Aug 28, 2006
    Be prepared to wait a while for the 35 Pass erase, its major overkill, the government couldn't even retrieve your files after that :D
  6. tmpmb thread starter macrumors newbie

    Jan 31, 2007
    LOL I'm not doing the 35-pass erase (I don't think I mentioned that anywhere on my previous post). I plan on doing the 7-pass erase but do you guys think "Zero Out Data" is enough?
  7. yuanmoons macrumors 6502

    Aug 7, 2008
    I recently changed laptops and did the following.

    1, Unauthorise your itunes account and backup

    2, Delete all absolute unique personal / private files securely via finder 1st. So maybe you have some folders that have personal docs in? Move all to trash then "Secure Delete".

    3, Then put the install cd's in and run the disk utility from there.... i think youve said this. I did 7 passes on a 160gb drive and it look 8+ hours so leave it running over night depending on your hd size.

    4, Install fresh os.
  8. tmpmb thread starter macrumors newbie

    Jan 31, 2007
    Your method looks pretty good. I think I'll go ahead and use your method :) Thanks!

  9. Objectivist-C macrumors 6502

    Jul 1, 2006
  10. muldul macrumors 6502

    Apr 21, 2008
    West Sussex, England, UK
    Why, may i ask?
  11. MarkMS macrumors 6502a

    Aug 30, 2006
    It's a waste because the buyer is, most likely, buying the machine so he/she can use it and not so they can harvest personal data.

    If you need more detailed information, check this blog post from a forensic analyst. They started a project to see how many passes are needed to correctly wipe a drive. The consensus is that a single pass is enough.

    Synopsis of blog post:

    "This study has demonstrated that correctly wiped data cannot reasonably be retrieved even if it is of a small size or found only over small parts of the hard drive. Not even with the use of a MFM* or other known methods. The belief that a tool can be developed to retrieve gigabytes or terabytes of information from a wiped drive is in error."

    *MFM=Magnetic Force Microscopy
  12. Meek Wriggle macrumors member

    Jun 10, 2009
    It's been proven now that most data can't be recovered after a single pass. And the data that can be recovered after a single pass is so garbled it's useless. I saw some article about it several months back on Reddit or Digg.

    EDIT: The poster above me explains it better. However, I'm pretty sure the article I read was different to his. Same thing though; anything over one pass is pointless.
  13. yuanmoons macrumors 6502

    Aug 7, 2008
    Glad i could help. :)

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