Bug: Windows 2000 corrupts MFT of disk larger than 137GB - Microsoft Windows

This is a discussion on Bug: Windows 2000 corrupts MFT of disk larger than 137GB - Microsoft Windows ; This is perhaps a well known problem but I had trouble finding any reference to it when searching the net so I thought I'd document it here for others googling. BUG: Windows 2000, regardless of service pack, will destroy the ...

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Thread: Bug: Windows 2000 corrupts MFT of disk larger than 137GB

  1. Bug: Windows 2000 corrupts MFT of disk larger than 137GB

    This is perhaps a well known problem but I had trouble finding any
    reference to it when searching the net so I thought I'd document it
    here for others googling.

    BUG: Windows 2000, regardless of service pack, will destroy the MFT
    without warning when trying to write to a disk past the 137GB limit
    unless the EnableBigLba key is added to the registry.

    WHY IT HAPPENS: People partition and format with a 3rd party utility
    that supports disks > 137GB and then install Windows 2000 which doesn't
    support large drives even with SP3. The problem probably still occurs
    (and probably sooner) if you make two smaller partitions, since it's a
    physical, not a logical disk problem.

    SOLUTION: Add the EnableBigLba registry key before filling the drive
    with data.


    LONG DESCRIPTION:

    Windows service pack 3 claims that it supports disks larger than 137GB,
    but as this KB article points out, that support must be manually
    enabled by editing the registry:

    http://support.microsoft.com/default...b;EN-US;305098

    When trying to install Windows 2000 pre service pack 3 to a drive
    larger than 137GB, you find that Windows Setup will only
    partition/format the first 137GB. The natural, but foolish response to
    this is to partition and format the disk with a 3rd party utility and
    then install windows. Under these conditions windows will install and
    run flawlessly and even report the drive size correctly in My Computer.
    But even after installing the latest fixes and service packs, the
    following stealthly bug occurs unless you manually add the EnableBigLba
    registry key as described in the above KB article:

    When the drive is filled with data, eventually Windows tries to write
    to sectors beyond the 137GB limit, but this fails because of a 28-bit
    address limitation. Instead it wraps around and writes to the beginning
    of the drive where the boot record and MFT are. This will not be
    immediately apparent. The drive will still be usable, allowing files to
    be created and read, but bit by bit, certain files will become
    inaccessible. Eventually the user starts seeing errors such as

    "C: is corrupt or unreadable"
    "C:\ path is inaccessible. the file or folder is corrupt and
    unreadable"
    "the file or directory C:\$MFT is corrupt and unreadable. please run
    the chkdsk utility"

    Upon reboot Windows fails to boot, or if the drive is not the boot
    drive, chkdsk runs and deletes half of the files on your drive because
    their MFT FILE entries have all been erased. This is an extremely nasty
    bug because it comes without warning and only AFTER your drive is
    filled with precious data. Here is a user discussion of the problem.
    The correct solution is at the end:

    http://www.techspot.com/vb/all/windo...e-help-me.html

    Service Packs do not solve the problem. One solution is to let Windows
    2000 partition and format the drive at 137GB and leave it at that.
    Making multiple partitions less than 137GB will not solve the problem
    but will probably make it occur sooner. The only solution is to
    manually create this registry value before the drive starts to become
    full:

    Location:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Atapi\Parameters
    Value name: EnableBigLba
    Data type: REG_DWORD
    Value data: 0x1

    Hope this saves some data out there. I lost everything twice before
    finally figuring this one out.

    Keywords: Windows 2000 service pack 3 large disk drive limit MFT
    corrupt NTFS 137GB 128GB


  2. Re: Bug: Windows 2000 corrupts MFT of disk larger than 137GB

    P.S. You must restart for the Registry setting to take effect.


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