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Solved: Interesting HD situation

Discussion in 'Hardware' started by gameman, Apr 29, 2010.

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  1. gameman

    gameman Thread Starter

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    I have a system with two hard drives. Here are the stats:
    Drive 1
    In Bios: Cylindars 1024, heads 255, sectors 63
    In Disk Director: Cylindars 14594, Heads 255, Sectors 63

    Drive 2
    In Bios Cylindars 1024 sector 63 heads 255
    Disk Director: Cylinders 16710, secors 63, heads 255 (viewed from Windows 2000)
    Disk Director Cyilinders 19458, sectors 63, heads 255 (viewed from Windows XP)
    (the system is dual boot).

    Now so far there is not any data loss from the second drive it is mainly a data storage and backup drive. Where the first one is a (dual boot) drive. However some data in folders are invisable in windows XP but you can see and use the data fine in windows 2000.

    The question is, what should I do next? I assume get the data off of the second drive as soon as possible. All tests and diagnostics (including spinrite) say that the drive is fine. The next question is if I put the second drive in another computer I have to assume that the data may or maynot be available and if it is, it may be corrupted when viewed in a another machine. Next question is, if I do try to have it viewed from another machine or in a enclosure, will that change the data on the drive any? As I understand it, no but I wanted to confirm.

    -GM
     
  2. Alex Ethridge

    Alex Ethridge

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    In XP, click Start> Control Panel> Administrative Tools> Computer Management> Disk Management. Does the drive show up there but without a drive letter?
     
  3. gameman

    gameman Thread Starter

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    The drive shows up with letters (also changeable if I wish). And most of the data is accessible from XP. Just several folders look empty rather than have the large ammount of files that are there just fine in windows 2000
     
  4. Alex Ethridge

    Alex Ethridge

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    If you have Windows XP Service Pack 3, I have no other suggestions on why the files are visible in Windows 2000 and not in XP.

    Neither Windows 2000 nor XP initial releases had 48-bit addressing capability. Windows 2000 got it with (I think) Service Pack 3 plus a manual registry edit. Windows XP got it automatically when (I think) Service Pack 2 was installed.
     
  5. gameman

    gameman Thread Starter

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    Hmm I did a bit of checking and apparently 48bit LBA was added in XP service pack 1 (http://www.48bitlba.com/index.htm). So yes it is definitely has it. It is odd considering that the partitions add up to less that 132. Problems or corruption (not seeing anything) should only occur if it is over that limit and 48bit LBA enabled on one OS but not the other. At least according to what I have read. But feel free to correct me if I am wrong.

    I am wondering if I put the drive in a USB enclosure if there would cause corruption or not. As far as I have read no, but has anyone here tried it (or something similar)? Sounds like something is amiss and I had better get all the data off and rebuild the drive (format, and clone the paritions back).
     
  6. Alex Ethridge

    Alex Ethridge

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    Here's what can happen when swapping OS. You set up the drive in the 48-bit environment and it does well. You then boot to the other environment that does not have 48-bit capability. That environment then can repartition the drive to 137-G or maybe corrupt the data or both. Then when you go back to XP, XP then has a problem reading the drive.

    Best scenario would be to get the data backed up if possible. Be sure both XP and 2000 are 48-bit capable. Reconnect the drive. Delete all partitions on the drive. Set up the drive from scratch (partition, format, etc.). Re-copy your data back to the drive and all should be well.

    I think maybe your Windows 2000 is not 48-bit capable. The 132 Gigabyte number you mentioned is suspiciously indicating that to me.

    Here are my notes on making Windows 2000 48-bit capable:

    The following conditions are necessary for 48-bit LBA ATAPI support:
    I. A computer with a 48-bit LBA-compatible Basic Input/Output System (BIOS) installed.
    II. A computer with a hard disk that has a capacity of greater than 137 gigabytes (GB).
    III. You must enable the support in the Windows registry by adding or changing the EnableBigLba registry value to 1 in the following registry subkey:
    IV. HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/atapi/Parameters

    To enable 48-bit LBA large-disk support in the registry:
    1. Start Registry Editor (Regedt32.exe).
    2. Locate and then click the following key in the registry:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Atapi\Parameters
    3. On the Edit menu, click Add Value, and then add the following registry value:
    Value name: EnableBigLba
    Data type: REG_DWORD
    Value data: 0x1
    4. Quit Registry Editor.

    NOTE: If you enable 48-bit LBA ATAPI support by editing the preceding registry key, but your system does not meet the minimum requirements, you may observe the following behaviors:
    Operating systems that do not have 48-bit LBA support enabled by default (such as Microsoft Windows 98, Microsoft Windows Millennium Edition (Me), or Windows 2000) that are installed on a partition that spans beyond the 28-bit LBA boundary (137GB) will experience data corruption or data loss.
    The installation of operating systems that do not have 48-bit LBA support enabled by default (such as Windows 98, Windows Me, or Windows 2000) on a partition that is beyond the 28-bit LBA boundary (137 GB) is unsuccessful and leaves behind a temporary installation folder.
    If you install hotfixes that enable 48-bit LBA before you install Windows 2000 Service Pack 3 (SP3), the appropriate registry key will be automatically created during the installation of SP3 to preserve the data integrity of the hard disk.
    After you enable 48-bit LBA support by adding the appropriate registry key, data corruption may occur if you remove the registry key or if you remove (uninstall) SP3 for Windows 2000.
    If you install a copy of Windows 2000 that includes SP3 (SP3 integrated) on a large hard disk that has already been preformatted by using a 48-bit LBA-enabled operating system, the ATAPI subsystem may report hard-disk space greater than that which is addressable without the 48-bit LBA support (larger than approximately 137 GB) during the text-mode portion of Setup. In this case, the hard disk's partition table information has already been created. To fix the incorrect disk information, delete the partition by using either a disk partitioning utility or by deleting and then re-creating the partition during the text-mode portion of Setup. After you create the new partition, quit Setup by pressing F3, and then restart the Windows installation process. The ATAPI subsystem now correctly shows approximately 137 GB of hard disk space.
    The EnableBigLba registry value is disabled:

    If you have a 48-bit compatible BIOS that can support a hard disk that has a capacity of more than 137 GB, only the first 137 GB of the hard disk is addressable. The remainder of the hard disk is not used.
    The operating system must be installed on the first partition that is smaller or equal to 137 GB when the EnableBigLba registry value is enabled but when you do not have a 48-bit LBA compatible BIOS.

    If you enable the 48-bit LBA ATAPI support by editing the registry setting, but you lack both a 48-bit LBA compatible BIOS and a hard disk that has a capacity of more than 137 GB, the hard disk continues to function as a standard hard disk with an addressable limit of 137 GB.
    The operating system must be installed on the first partition that is less than or equal to 137 GB and the rest of the hard disk divided into one or more remaining partitions when the EnableBigLba registry value is enabled on a computer without a 48-bit LBA compatible BIOS that has a hard disk with a capacity of more than 137 GB.
     
  7. gameman

    gameman Thread Starter

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    Thank you very much for all the information. And bascially confirms what I thought. But as I understand it if you don't go over the 137 limit (total amount with various partitions and all of them smaller that 137) then data corruption won't occur? I did check and that the bios does indeed have 48 bit addressing. Another question, do you know if a USB external drive would also have the same issues with the 137 limit? I seem to recall reading somewhere that it didn't affect USB external drives.
     
  8. Alex Ethridge

    Alex Ethridge

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    If you have a disk that is larger than 137 Gigabytes and it is connected to a machine with a 28-bit addressing limit, you will be able to use only the first 137 Gigabytes of that disk.

    Example: You have a 500-G disk connected to a machine with 28-bit addressing, the upper 363 Gigabytes are of no use. It's just lost space.

    The limit to what your system will see in a USB enclosure is defined by a chip in the enclosure. Example: Put a very new large drive into a very old USB enclosure and you might have a problem.
     
  9. gameman

    gameman Thread Starter

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    Yes that is what I understood. I was just wondering that if the USB enclosure could bypass the situation, but I see that is not likely (or very unusual effects are going to happen).

    I did mange to get all the data from the drive. And after I turned on 48bit addressing in windows 2000 the same files/folders that disappeared while running XP were now missing as well. Obviously this was the problem. I deleted all partitions and rebuilt the drive using Disk Director9. It seems to be working fine now.

    Thanks for all the help and information.

    -GM
     
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