New hard drive to be safe?

Discussion in 'iMac' started by anncfg, Jun 7, 2010.

  1. anncfg macrumors newbie

    Jun 7, 2010
    My ex-husband has downloaded some questionable things over the past year. If I install a brand new hard drive and destroy the current one, will all traces of his activities be gone? Just like getting a new computer? Thanks.
  2. miles01110 macrumors Core


    Jul 24, 2006
    The Ivory Tower (I'm not coming down)
    Yes. Although it seems like hard drive replacement isn't getting to the root of the problem...
  3. flatfoot macrumors 65816

    Aug 11, 2009
    Actually, there is no need to destroy the hard drive. Just erase it with Disk Utility. Under "Options" you can set it to overwrite everything with zeroes. Usually, one pass is enough to make it impossible for consumer data recovery programs to restore the data. If you have the time, do a 7-pass. I don't think 35-pass is necessary.

  4. Yamcha macrumors 68000

    Mar 6, 2008
    Yeah, I would just format the drive.. and I don't think there is any need to worry, regardless of what he has downloaded whether its illegal or not :p.. nobody can do anything about it..
  5. Phantom Gremlin macrumors regular

    Feb 10, 2010
    Tualatin, Oregon
    just how "illegal" was the old content?

    Title is rhetorical, I don't want to know.

    Secure erase doesn't completely erase a drive, but only about 99.99%. During normal operation, sometimes drive sectors "go bad". What that means is the drive must employ its data recovery algorithm to retrieve the old data. When that happens the drive will automatically rewrite the recovered data into a new sector so that it can be retrieved more readily in the future.

    Secure erase won't erase old data from those "bad" sectors, since they're no longer visible to the operating system. But the data there is either 100% recoverable or at least 99+% recoverable by people with the right expertise.

    So, if had something of national security interest to erase, e.g. the US Army guy recently arrested for leaking classified documents, I'd be worried about every single sector on my laptop. That comes under the category of "don't mess with the Eagle".

    Also I wouldn't bet against a determined enough adversary (e.g. "the Eagle") recovering traces of data from an erased sector, even if you overwrite it using secure erase. The heads won't be exactly aligned on the rewrite. So maybe 1% of the old data of some sectors might be recoverable by the right equipment and technique, maybe 50% of the old data of other sectors. Even if you recover just 20% of the data from just a handful of disk sectors, that might be enough to prove that something really bad (e.g. a classified document, or child pornography) was once on the drive. Physical destruction of the disk platters is the only way around that.

    But if it's just run-of-the-mill "questionable things" a typical ex-husband would do, then secure erase should be more than adequate, and save the expense of a new hard disk.
  6. ClassicII macrumors 6502


    Sep 21, 2009
    Chicago, IL
    Yes, I would do a 7 pass US Department of Defense Wipe. Not really any chance that someone would find anything after that.

    or.... smash it with a hammer and ship it to him in a box and then use it as a good excuse to upgrade to a bigger hard drive :)
  7. Sun Baked macrumors G5

    Sun Baked

    May 19, 2002
    Delete all the bad files, use the bookmark manager to save a copy of the bookmarks then trash all the Firefox or Safari application support/preference files.

    Use the command-F and the sidebar to show all movies and pictures and see if everything is gone.

    Once you kill all the bad stuff, you can do a clean Time Machine backup, then wipe and restore stuff.

    If you are still worried, and want to leave crap on the drive, download a couple different Barney music videos, just duplicate these on the desktop a few times, toss them in a folder, duplicate the folder a few times, and keep doing it until the drive is full, then toss these files in the trash and empty.

    If somebody want to sort through 100s of hours of Barney singing "I love you, you love me ..." more power to them.
  8. 300D macrumors 65816


    May 2, 2009
    Completely pointless. A single pass will wipe out all data beyond any possible recovery.
  9. TMRaven macrumors 68020


    Nov 5, 2009

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