How can a full format/low-level format be done on an SD memory card?

Discussion in 'Digital Photography' started by itsme.ultimate, Nov 20, 2005.

  1. X-No-Archive: Yes

    One of my cameras only have the option to do quick format. I have a
    data recovery software for SD media and it picks up most of the photos
    in the card following the quick format on the camera or Windows format.

    I also have a Canon SD400 which has an option called "low-level
    format" that's intended to be used when the writing speed in motion
    picture or continuous shots becomes slow. The data recovery software
    was unable to recover pictures after the card was formatted using this
    option.

    There are things I don't like about the SD400 and I'm selling the
    camera, therefore I need to find an alternative way of low-level
    formatting SD memory cards. Are there utilities out there that will
    allow me to do full formatting comparable to SD400 through my card
    reader?
     
    itsme.ultimate, Nov 20, 2005
    #1
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  2. itsme.ultimate

    Rudy Benner Guest

    Rudy Benner, Nov 20, 2005
    #2
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  3. Itsme-

    A low-level format serves the purpose of deleting data from the card,
    since its layout is essentially hard-wired. Therefore, you might write
    large, meaningless file(s) to the card to over-write existing data, and
    then do the simple format to reset the directory.

    If you do this, the directory may still contain parts of previous image
    file names, but there won't be any files that can be recovered other than
    the one(s) you used to overwrite the previous data.

    Fred
     
    Fred McKenzie, Nov 20, 2005
    #3
  4. Itsme-

    I just bought the SD400. It seems like a nice camera and images look OK.
    I would be interested in your complaints.

    Fred
     
    Fred McKenzie, Nov 20, 2005
    #4
  5. itsme.ultimate

    Bill Funk Guest

    I'm not sure what it is that you want to accomplish.Is there something
    about a "low-level format" that you need? Or is it that you want to
    "erase" the card's contents?
    If the latter, use your card reader to write a large file (or several
    files) to the card, enough to fill it; this will overwrite any other
    data, making it unretrievable to all but the most determined. If this
    is evidence of a felony you want to erase, do the above a few times,
    and not even the FBI will be able ot retrieve it.
     
    Bill Funk, Nov 20, 2005
    #5
  6. itsme.ultimate

    Dave Cohen Guest

    That FBI comment is interesting. On magnetic media, erased or overwritten
    data recovery (ie disk or tape) relies on sophisticated techniques involving
    capturing residual data not completely overwritten. This is a function of
    magnetic recording. I've never seen any comments regarding solid state
    memory and wonder if such things are possible. When people tell me how
    readily erased data can be recovered I think back to the infamous Nixon
    tapes. I don't think they ever got much out of those erased portions and
    they had the best people working the problem, so I question the whole
    subject. I am aware of the theory, but have no data to judge how well that
    translates into practice.
    Finally, don't confuse the above with specialist data recovery services that
    can often be helpful for damaged or formatted drives.
    Dave Cohen
     
    Dave Cohen, Nov 21, 2005
    #6
  7. itsme.ultimate

    Bill Funk Guest

    Damaged and formatted drives are very different from drives that have
    been ovewritten. They are easy compared to overwritten drives.
     
    Bill Funk, Nov 21, 2005
    #7
  8. itsme.ultimate

    kashe Guest

    If you're that paranoid, you can first write enough small
    files to fill up the entire directory with bogus filenames.

    But, if the existing names are all of the form IMG_0001 or
    similar, why do you care anyway?
     
    kashe, Nov 21, 2005
    #8
  9. itsme.ultimate

    ASAAR Guest

    Much easier compared to overwritten drives. But with enough care,
    information can be extracted from overwritten drives. Very slight
    mechanical positioning errors of the drive's write heads makes this
    possible. The original read heads are not used, of course. Very
    precise, highly accurate, narrow heads are used that cover a much
    smaller part of the track. It's similar to, but not quite the same
    as using an extremely narrow bandwidth on a radio to help eliminate
    closely adjacent signals, whether QRM or QRN. I doubt that this
    kind of equipment is used by most data recovery services. I don't
    know how data could be recovered from flash cards after completely
    overwriting its memory. The key word is "completely". If you don't
    write the right size files, there will be "slack" space on the card
    that wasn't overwritten.

    I once wrote a DOS program that quickly fills drives with
    predictably changing data patterns, where the size of the files are
    easily controlled. It was originally used to test the (at the time)
    gigantic 2MB bank-switched memory boards for the IBM PC. Some of
    them were flakey, and a file written to one location on the memory
    board could sometimes surface in more than one location due to buggy
    hardware. Nowadays I just use the program to either quickly create
    space-wasting files on hard drives, or (with the file size set to
    zero) quickly create multiple directory entries.
     
    ASAAR, Nov 21, 2005
    #9
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