In process of 7-pass erase... may have gone wrong... advice please?

Discussion in 'macOS' started by Miss Terri, Nov 18, 2010.

  1. Miss Terri macrumors 6502

    Joined:
    Nov 11, 2010
    Location:
    US East Coast
    #1
    Hello, and thanks in advance for any help you can provide. (By the way I did search and did not find the answer to my question.)

    So, I've sold my white unibody Macbook and so I am erasing the drive. I read quite a few articles, and most recommended the 7-pass erase.

    I put in the system disk, held down C, and started it. After quite some time and a lot of disc noise, it came up, I chose my language, and then went into disk utility. The first question I had was ... do I select the overall drive "250gb Toshiba" or the indented one under it "Macintosh HD." From the information I could find in searching, it sounded like I should choose "Macintosh HD," so I did (more on that in a minute).

    I did that, chose the 7-pass radio button, and then erase. It started erasing and said something like "Pass 1 of 7; estimated time 5 hours." That makes it sound like the whole thing would take 35 hours :eek: (I have 100gb of data; it's a 250bg hard drive.)

    Edited to add: Okay, just as I was about to post this, it went to "Pass 2 of 7; estimated time 6 hours." It's only been about two hours, so maybe that is the total time (not worded very well if so).


    Uh-oh, I have this set up on my desk at work and it can't be here for two days!

    I also read that making 7 passes is hard on the drive. I'm selling this to a friend, so it's not going into dangerous hands (although who knows, maybe he'll sell it in a year...).

    So.... should I now press the "skip" button? I don't want to wear out the drive. I also don't want my computer erasing for days (overnight would be okay and is about what I expected). But I do want at least one secure erase pass. If I press skip will the one erase it already did be as good as if I had chosen one erase in the beginning?

    Back to the drive I selected (Macintosh HD). I don't have any partitions or anything. Just your basic install and data. Have I done this properly? Should I start over and select "Toshiba" instead?

    You know I Googled and read many documents, and I know this is probably simple for experienced computer folks, but it's new for me.

    Thank you,
    Terri
     
  2. Intell macrumors P6

    Intell

    Joined:
    Jan 24, 2010
    Location:
    Inside
    #2
    The Zero pass is good enough for most people. If you've gotten at least two of the seven passes in then I'd say the data is erased good enough.
     
  3. Mwongozi macrumors member

    Mwongozi

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    Sep 17, 2007
    Location:
    Woodside, CA
    #3
    It is physically impossible to recover data from a disk after a single complete pass.

    One pass is enough
     
  4. Miss Terri thread starter macrumors 6502

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    Nov 11, 2010
    Location:
    US East Coast
    #4
    Okay, so I can click on "skip" and all will end well?

    Also, what about the fact that I selected the "Macintosh HD" instead of the Toshiba "mother" disc? (Would there be data on the Toshiba that was not on the Macintosh HD?)

    Thanks,
    Terri

    (Partway through pass 2 of 7 on Macintosh HD....)
     
  5. Mwongozi macrumors member

    Mwongozi

    Joined:
    Sep 17, 2007
    Location:
    Woodside, CA
    #5
    Yes. Skip and feel safe.

    If "Macintosh HD" is the only partition on the disk, then you're fine.
     
  6. Miss Terri thread starter macrumors 6502

    Joined:
    Nov 11, 2010
    Location:
    US East Coast
    #6
    Thank you all so much for not only the good info, but ... so quickly!

    Since I do have some spare time here, I guess I'll let it finish pass two and then "skip."

    Unless someone chimes in otherwise, I'll assume I don't have to hit any magical moment, but can "skip" whilst into pass three.

    Not sure what window or choice I'll get then, but if it's confusing and Googling doesn't solve it, I may post back :)

    Then, I think it's on to the install of the first system disc (the one have in it now) and then Command-Q when I get the welcome screen (so my friend will have the New experience since he's just coming to Apple (from Windows ME :eek: ;) :D).

    I believe he will then install the applications disc himself (since if I do that I'll be past the "new!" part.

    Then buff it up, pack it, and out the door.

    Terri
     
  7. Miss Terri thread starter macrumors 6502

    Joined:
    Nov 11, 2010
    Location:
    US East Coast
    #7
    Follow-up

    I just thought I would follow up to say that I did click on "skip" at about four passes when I was ready to move along. That worked fine.

    Then I had a moment where I couldn't figure out how to get from there to the install part. Googled....no. Then, duh!, I remembered that I was in the disk utility pane, so I closed that and.... whew.... there were the install options I was looking for.

    The only other thing of note is that all of the "prep your mac for sale" articles I had read said that when the music and "Welcome" graphics started playing, to hit Command-Q and exit, then eject the disc, and then the new owner would get the whole new "Welcome" experience when they started up the machine.

    Well I hit Command-Q and the music just kept on playing. Command-Q.... Command-Q..... nope. Gaah. Now I can't remember exactly what happened, but eventually it went to the screen where you start to choose things and log in. I quit from there (it does work from that screen) but then somehow shut down and then the disc would not eject (of course).

    So I started up again (and the Welcome screen did start at the beginning so I know that's working), tried Command-Q during the music for the heck of it (like they say to do), but same thing it had no effect. When the next screen came up Command-Q did work, and then I ejected the disc before shutting down and all was okay.

    So.... just a little different from what I'd read, but now she's on her way to her happy new owner :)

    Next..... get my new MBP set up and running. I may be posting back with a few questions :D (Will search first though!)

    Thanks for the help everyone :)

    Terri
     
  8. wpotere Guest

    Joined:
    Oct 7, 2010
    #8

    LOL, you keep thinking that... Clearly because it is on the internet it is true. I have seen 3 and 4 wiped drive have data pulled off of them. It is all in the tools that you have.
     
  9. Mwongozi macrumors member

    Mwongozi

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    Sep 17, 2007
    Location:
    Woodside, CA
    #9
    You're a liar. Prove it.
     
  10. qwerpafw macrumors newbie

    Joined:
    Jul 9, 2002
    #10
    This is a false statement. It is impossible to recover data from modern hard drives after they have been overwritten once.
     
  11. wpotere Guest

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    Oct 7, 2010
    #11

    Can't as it is my job and gov related, but it can be done. Believe it or not, I don't care.
     
  12. mac2x macrumors 65816

    Joined:
    Sep 19, 2009
    #12
    I might have believed you if you had qualified your statement to mean older, less dense disks from years ago.

    I understand that modern HDDs are far too dense for standard computer forensic techniques to recover data from, once a single pass erase has been carried out.
     
  13. hollerz macrumors 6502a

    hollerz

    Joined:
    Sep 13, 2006
    Location:
    Durham, UK
    #13
    Thumb drive (SSD) is a different ball game to HDD.
     
  14. SidBala macrumors 6502a

    Joined:
    Jun 27, 2010
    #14
    Unless if you are part of the CIA or the NSA or whatever with very top secret documents, you should do a zero pass delete.

    Zero pass - drag your stuff over the trash, and then empty it.
     
  15. mac2x macrumors 65816

    Joined:
    Sep 19, 2009
    #15
    This may be true (we have no way to prove it), but a response like that certainly could be put down as a "convenient excuse". ;)
     
  16. wpotere Guest

    Joined:
    Oct 7, 2010
    #16
    Very true... I would say that for common usage a one time wipe should suffice but I would not say that it will not be retrievable. ;)
     

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