35-pass erase?

Discussion in 'MacBook' started by sunsnewmac, Jan 20, 2011.

  1. sunsnewmac macrumors 6502

    sunsnewmac

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    Mar 3, 2007
    #1
    I am giving my old MB to a family member, I want to wipe it clean but don't have the CDs and need to get rid of it within a matter of days so don't have enough time to get new ones. I figure that using Disk Utility is good enough for the job, but how long does the 35-pass erase take, anyway? I've heard it takes "forever," but what does that mean? Is it going to stall and I won't know if it finished or not? Can't risk sending him a dead machine with no boot CDs so what are my options? I want to do as secure an erase as possible because I've got lots of sensitive data (banking info, etc). Any 3rd party software that would be better to use? Any other suggestions on how to securely erase data and give the computer in "new" condition?
     
  2. miles01110 macrumors Core

    miles01110

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    #2
    It's unnecessary to do anything more than a 7-pass erase.
     
  3. SandboxGeneral Moderator

    SandboxGeneral

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    #4
    Well just as you said, the 35 pass option will take forever and if you have only a few days before you have to turn it over, you may consider not using the 35 pass method. The 7 pass method is the DOD standard for erasing magnetic media so I think that the 35 pass is more than overkill.

    See the attached screen capture from Disk Utility for explanations of the different security options in erasing a drive, if you haven't already looked at it.

    I think you'd be fine with the Zero Out Data option. That will still probably take the better part of a day depending on the size of the disk. But if you think they will take your computer to the NSA or bring it to some HDD recovery specialists and pay $1200 or more to recover your data, then by all means go with the 7 pass or 35 pass method.

    But if I were that worried about it, I would take the HDD out and literally shoot it up with one of my rifles. Then I would buy a new HDD, put it in and say "here you go, all it needs is an OS."
     

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  4. sunsnewmac thread starter macrumors 6502

    sunsnewmac

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    Mar 3, 2007
    #5
    Thanks guys, I didn't know the zero out alone would take a full day, that was exactly the info I was looking for. How long would the 7-pass take, about? I'm giving it to a family member so should not be too paranoid but who knows what he will do with it next or whose hands it will fall into and I can't risk my sensitive data being compromised...

    Ancillary question: what about targeting specific files for the complete wipe-out? Or keychains and a few other things and just forget the rest of the contents?
     
  5. marksandvig macrumors regular

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    May 21, 2006
    #6
    I sold my MB last year and did the 7-pass with a 160gb 5400 rpm it took a full night.
     
  6. chaoticbear macrumors 6502

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    Jul 25, 2007
    #7
    What are the odds this family member is going to try and recover the data from the hard drive? That's the part that gets me.
     
  7. mr.steevo macrumors 65816

    mr.steevo

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    Jul 21, 2004
    #8
    If you don't have the install disc will the family member be buying a new install disc? If so you could, as was mentioned, give them the computer without a hard drive and they could buy a new one and install 10.6 with their new disc.

    The other question I have is the sensitivity of your data. If you are just concerned about certain files then you could throw it in the trash and select Secure Empty Trash http://www.apple.com/pro/tips/empty_trash.html then delete your account with another Administrator account.

    If you are really concerned about your private information then I'd go with the first option and let the family member buy a new hard drive. HDD's fail all the time so now is a great time to upgrade.
     
  8. sunsnewmac thread starter macrumors 6502

    sunsnewmac

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    #9
    Thanks for all your help guys.
    The family member is money-sensitive so unlikely to afford a new hard drive in the near future. He probably won't try to recover any data but who knows who else handles the computer after him--that's what I'm trying to protect against.
    Performing a secure delete for files I am concerned about and also deleting admin account are great options. At the same time, I can certainly handle a full night if that's what a 7-pass takes. Does the 7-pass erase the admin accounts and basically freshen it up so it's nearly like new?
     
  9. iThinkergoiMac macrumors 68030

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    #10
    You have absolutely nothing to worry about. Zero out the data and you'll be perfectly safe. It would be ridiculously difficult to get any data off it immediately after, and even more so after it's been used for a while.

    Any erase does just that, it erases the drive. So anything on the drive before won't be there any more. A quick erase will leave all data behind, a zero-out data erase will get rid of everything, and anything beyond that will be superfluous. If you're really worried, you can do a 7-pass erase, but either one will be just fine.
     
  10. sunsnewmac thread starter macrumors 6502

    sunsnewmac

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    #11
    Excellent! One last question: will doing the zero-out (or 7-pass) retain the iLife software and whatever else came originally with the OS when I bought the computer?
     
  11. simsaladimbamba, Jan 22, 2011
    Last edited: Jan 22, 2011

    simsaladimbamba

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    #12
  12. SandboxGeneral Moderator

    SandboxGeneral

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    #13
    No. You will erase everything on the the drive. It will become blank and a reinstall of the OS and all applications and files will be required.
     
  13. simsaladimbamba

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    #14
    As one can't erase a partition one is booted from, the OP won't likely be able to do so without a DVD, as he or she is using the ERASE FREE SPACE option, most likely, as there is no other option without a DVD anyway, unless one cloned the system though.
     
  14. Heath macrumors regular

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  15. sunsnewmac thread starter macrumors 6502

    sunsnewmac

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    Mar 3, 2007
    #16
    Glad I checked! I can't give him a blank computer with no OS or iLife, that would defeat the purpose. So how about this: Create a new Admin account, delete my current account from there (and all library files), then securely empty trash. Will that do the trick?
     
  16. simsaladimbamba

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    #17
    It would do the trick too.


     
  17. sunsnewmac thread starter macrumors 6502

    sunsnewmac

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    #18
    follow-up:

    Did it the easy way and it went faster than expected. Just deleted my user account, safely emptied trash and performed a 7-pass and it only took half a day. Computer is packed and ready to be gifted. A million thanks for all your help guys!
     
  18. SandboxGeneral Moderator

    SandboxGeneral

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    #19
    I'm glad it all worked out for you.

    Cheers
     
  19. milocool macrumors newbie

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    Jan 8, 2013
    #20

    I just did that :( i had about 1.9 gig available on that partition, it went down to 0 and i didn't recover it after the "ERASE FREE SPACE" was done, is there any way to recover that space?

    (it's probably a temporary file i'm guessing but how do i find it) :s
     

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