Secure erase before clean install of Lion?

Discussion in 'Mac OS X Lion (10.7)' started by advaitan, Jun 19, 2011.

  1. advaitan macrumors newbie

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    Jun 19, 2011
    #1
    Just got a 2011 MacBook Pro, planning on upgrading to Lion once it's released next month for public consumption. I have an Apple SSD in the MB Pro, and my question is about performing a secure erase of the SSD before upgrading to Lion from Snow Leopard. Is it necessary? Would you guys recommend doing a secure erase as opposed to just a simple reformat before upgrading? Any harm in doing a secure erase on the Apple SSD?
    Thanks in advance for any info.
     
  2. Atarikid macrumors regular

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    May 14, 2011
    #2
    Depends which SSD you have.
    If it has a Sandforce controller, it is not necessary.
    All other controllers should benefit by a factory reset. As far as I know this can only be done with a PC. So, you have to disassemble the SSD and put it into a PC. Mostly you can find the needed tool in the download sections of the manufacturer.

    EDIT: didn't read you got a Apple SSD. Not sure which controller they use. But I do not think it is a SandForce controller.
     
  3. advaitan thread starter macrumors newbie

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    Jun 19, 2011
    #3
    Thanks for the reply. Yea, it's an Apple SSD which definitely is not Sandforce. It does however have TRIM support. I can do a secure erase from the Disk Utility, so not sure about what you're saying about taking it out and putting into a PC... Just wondering if anyone has thoughts about it being useful with a TRIM enabled SSD to secure erase before upgrading to Lion, and if there are any negatives associated with secure erase of Apple SSD. Thanks.
     
  4. Atarikid macrumors regular

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    #4
    No, do not do a secure erase because it 'kills' (read: slows down) SSD. It just writes zeros on all blocks. Something you do not want for SSD.
    The only way to really secure erase a SSD is to use the appropriate tools (factory reset). ATM there no available for OS X.
    That is why you have to do this with a PC (sad but true).
     
  5. advaitan thread starter macrumors newbie

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    Jun 19, 2011
    #5
    Ok, I see what you're saying. So most would recommend just performing a simple reformat before doing a clean install of Lion then? Any one have any experience/recommendations after using DP4 regarding this?
     
  6. baryon macrumors 68040

    baryon

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    #6
    Why secure erase it? Are you afraid someone will steal your data? If so, continued usage of your new OS will overwrite all the data eventually.
     
  7. advaitan thread starter macrumors newbie

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    #7
    No, not worried about someone stealing anything, more interested in performance issues related to a clean install with or without a secure erase first... on an SSD especially. Thanks for the reply, any other thoughts guys?
     
  8. Atarikid macrumors regular

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    May 14, 2011
    #8
    Overwriting on a SSD is not enough to keep it optimal performing. That is one of the disadvantages of SSDs. Installing over a SL partition can result in slower SSD perfomance.

    A ATA command secure erase is the only way to get a clean SSD.
     
  9. advaitan thread starter macrumors newbie

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    #9
    interesting, thanks. "ATA command secureerase" versus a 1-pass secure erase via Disk Utility, how do they differ?
     
  10. Atarikid macrumors regular

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    May 14, 2011
    #10
    Not easy to explain in two words.
    Just do some Googling with 'SSD secure erase' and you will find buckets load of info.
     
  11. Maclver macrumors 68020

    Maclver

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    #11
    Secure erase via Disk Utility writes 0's on the disk so data can't be recovered. ATA Secure erase sends the command to the SSD and marks each cell as empty so essentially its like nothing was ever written on the disk. Just like a factory reset...
     
  12. Maclver macrumors 68020

    Maclver

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    #12
    There is an option available to Mac..


    http://forums.macrumors.com/showthread.php?t=841182

    Works on MBP as well!
     
  13. advaitan thread starter macrumors newbie

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    Jun 19, 2011
    #13
    great, thanks for the tip MacIver, I'll definitely check it out

    so as to my original question, is this something that would be beneficial/necessary/harmful to do prior to doing a clean install of Lion from Snow Leopard? just in terms of performance/stability, again not concerned with data recovery or anything like that? or is a simple reformat sufficient?
     
  14. Maclver macrumors 68020

    Maclver

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    #14
    Honestly I would do it if your going to do a clean install.. that way your drive starts out fresh and at top performance!
     
  15. advaitan thread starter macrumors newbie

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    Jun 19, 2011
    #15
    do which, the Disk Utility secure erase or the ATA 'SSD reset'?
     
  16. ScubaCinci, Jun 20, 2011
    Last edited: Jun 20, 2011

    ScubaCinci macrumors 65816

    ScubaCinci

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    Cincinnati OH
    #16
    This is not true at all. A secure erase sets the drive back to full performance as it came from the factory. It's about the only way to do it except for a destructive firmware flash which is rare these days.

    This is a great tool for secure erasing...http://blog.corsair.com/?p=4484. I use this method for securing erasing when doing SSD reviews unless the drive comes with a secure erase utility like Intel and OCZ.

    To answer the OP, you don't really need to TRIM though it won't hurt. Once Lion is installed and TRIM present, it should take care of cleaning the drive. Even though SL didn't support it, the drive controller has tracked all the dirty blocks and will execute the TRIM command against them.
     
  17. Atarikid macrumors regular

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    May 14, 2011
    #17
    I was referring to the Secure erase feature of DU. That is NOT good for SSD.
    A ATA secure erase is good.
     

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