Convert RAID to IDE?

Discussion in 'Asus' started by Bill Anderson, May 19, 2012.

  1. I'm running an Asus P5Q Pro Turbo and everything is working fine. I
    think I'll do a Socket 2011 build one of these days, but not now.
    Instead I keep upgrading my current system with things like the 3TB
    Seagate HDD I installed earlier this week.

    The new drive is working fine now, after a little bit of unexpected
    fiddling on my part. My system didn't know what to do with a 3TB drive,
    but I figured out an inelegant workround. And now I have a question.

    First some brief background. When I built the system a few years ago I
    wanted to use RAID to join two 1.5TB drives into one big 3TB drive.
    That meant choosing RAID in BIOS instead of IDE. I accomplished what I
    wanted -- heck, I successfully joined three 1.5TB drives into a 4.5TB
    RAID drive, but the RAID array fell apart and I lost a lot of work.
    (Nothing I couldn't replace, as I had backups.)

    So I just gave up playing with my MBO's flaky RAID and went back to a
    configuration I was more comfortable with. I am currently booting from
    a 1TB drive (the largest possible, I think) and using my new 3TB drive
    plus two 1.5TB drives for data storage, video editing, etc.

    But...and this is the root of my question...when building the system I
    had already begun installing my OS (actually I triple-boot, so it's
    three OSs) using the RAID controller on my P5Q MBO, and I just left
    things that way because I discovered that when I set BIOS back to IDE,
    my already-installed OSs wouldn't boot. (Windows 7 freezes when the
    fireflies begin to appear; use BIOS to set things back to RAID and Win7
    boots just fine.) And if you want to know why I didn't go back to IDE
    when I switched from XP to Vista to Win7 over the years, well, I dunno.
    Things were working fine? I didn't know better? Laziness? Take your

    Anyway, for all this time, running under the RAID controller without
    actually having a RAID array hasn't been a problem. I don't see drives
    in my main BIOS screen -- I have to hit a function key (F10? Maybe,
    something like that) to bring up a RAID screen at boot, and from there I
    can check on my drives. No problem, really. Until this week.

    Turns out the RAID controller wouldn't see all 3TBs of the new drive.
    It would claim the drive was something less than 1TB, I don't remember
    the size exactly.

    So...I ensured the new drive was initialized GUID, disconnected all HDDs
    from the MBO, set BIOS to IDE, connected an empty spare drive, installed
    Win7 64-bit on it, connected the new 3TB drive, and voila! I was seeing
    all 3 terabytes (actually somewhat less, but we all know how that goes).

    Then I split the drive into two equal 1.5TB partitions, disconnected the
    spare drive with the new Win7 installation, set BIOS back to RAID,
    re-connected all the drives (including the new 3TB drive), and I was in
    business. The RAID controller had no trouble dealing with a 3TB drive
    divided into two 1.5TB partitions.

    So all is well...for now. It's just that I am thinking of replacing my
    other two 1.5TB drives with 3TB drives, and I wouldn't want to partition
    them. I'd want them to remain 3TB.

    But I can't do that under RAID. And I can't simply switch back to IDE
    in BIOS because when I do, my OSs won't boot.

    Yes, I know I could just rebuild my OSs from scratch under IDE, but
    golly that would be a lot of work if there's a simpler way.

    Anybody know a simple way to make an OS built under RAID operate under
    IDE? Maybe? I hope? Thanks.
    Bill Anderson, May 19, 2012
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  2. Bill Anderson

    Paul Guest

    Windows 7 has a "driver reset" feature, to have the OS "reconsider" the
    driver it's using.

    The first time Windows 7 boots, it installs a driver, but also disables
    detection of the other unused drivers.

    A user can go into the registry and reset that, so that on the next
    boot, the OS will reconsider its choice. If you go into the BIOS, switch
    from RAID to IDE, then the IDE driver can pick up. Example of a recipe, here.

    Some keywords: pciide, msahci, iaStorV, iaStor, CurrentControlSet, (driver rearm)

    Obviously, if the information format on the disk is different, between
    a RAID drive and an IDE, such a scheme would fall flat on its face.
    (So you couldn't go from two drives in a RAID 0 to one IDE drive,
    because each drive only has half the necessary information.)

    If, on the other hand, the metadata used by the RAID is stored in a place
    not normally offered while in IDE mode, then the two driver options
    can be compatible enough that such a switch is possible.

    You seem to be aware of the 2.2TB limit, by nature of the fact you
    mentioned GUID partitioning. It's the kind of thing, that it pays to
    test the setup can really cross that barrier and survive. I've run
    into at least one poster "working without a net" as it were, who copied
    some media collection onto a large RAID, only to have the partition
    corrupted just as it went past being 2.2TB full. And without backups,
    the person was screwed. (Think of the fun running a file scavenger on
    a disk that size... Scavengers are slow even on tiny drives.)

    The disk manufacturers have two different solutions for 3TB single
    disk drives. One of them offers a horrible solution, which chops
    the disk into three partitions ? It's a driver level hack of some
    sort. The other driver offered, isn't quite as horrible. So check
    the disk manufacturer site, for another solution besides GUID.
    That kind of hack, is so you can boot from the 3TB. If you were
    dual booting Windows and Linux, such driver level hacks don't help
    matters, when you need to look at the disk in Linux. The disk
    manufacturers aren't likely to offer Linux solutions (and I haven't
    gone looking for such either).


    For OSes like Win2K or WinXP, changing drivers is more of a hassle, because
    of the "chicken versus egg" problem. You can't install a new driver,
    until flipping the BIOS setting. You can't boot the system, if you flip
    the BIOS setting. There are recipes out there to get around this,
    but not nearly as easy to do as the driver rearm in Windows 7.

    Paul, May 19, 2012
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  3. Thanks for the tip, Paul, but no joy.

    I was aware of the 2.2TB limitation when I started all this and I
    intended to divide my 3TB disk into two equal partitions all along, so
    basically I should be happy now. Also note that I am not running any
    drives "RAIDed" together. No RAID array. I'm running just individual
    drives using the RAID controller. It shows every one of my drives as

    But I have been experimenting with the info contained in the link you
    provided and others I Googled, such as
    and I've run up against a brick wall. Another fellow in this link seems
    to have the same problem I have: He installed Win7 using a RAID
    controller instead of IDE. It turns out that the registry edits don't
    work if you're trying to go from RAID to IDE or AHCI. They work the
    other way 'round though.

    I proved this by disconnecting my boot drive and connecting that spare
    drive I told you about, the one onto which I have installed Win7
    Ultimate 64-bit using IDE. When I made the registry edits on this drive,
    I could choose the RAID controller in BIOS, or AHCI or IDE, and Win7
    would happily recognize all my drives, install drivers, and require a
    reboot. Works great. I can have RAID if I want it or IDE or even AHCI.
    Just set what I want in BIOS and I'm in business. (Or Bob's your
    uncle, as one of the posters said.)

    But no such luck with Win7 installations that were set up under the RAID
    controller. It seems I can't go back from there, no matter how I change
    the registry using the instructions you found. Win7 will even boot
    using the RAID controller when the registry key for RAID (iaStorV) is
    set to 3, which should block it, one would think.

    Looks like if I want to install full 3TB disks in my system, I'm going
    to have to go through the humongous hassle of completely reinstalling
    OSs and applications. Maybe I'll drop 32-bit this time around. I think
    there are no longer any applications that I need to run in 32-bit. I no
    longer need my 32-bit drivers for the software I've used for years to
    capture Hi-Def cable broadcasts via FireWire. I have a Hauppauge
    capture card now that does what I need in that regard and it doesn't
    need 32-bit. So I guess I can give up my FireWire capability. And I
    suppose I can move iTunes from my 32-bit installation to 64-bit, even
    though it'll count the move as a switch of computers. I think there's a
    limit to the number of times I can do that, and I've already done it a
    few times. I hardly ever use 32-bit anymore. Maybe it really is time
    to give it up.

    Thanks for your help. If you have any other ideas, please let me know.
    Bill Anderson, May 19, 2012
  4. Bill Anderson

    Paul Guest

    OK. Let's assume it's a data layout problem.

    You could:

    1) Do the driver rearm procedure (has to be done before each attempt
    at changing drivers).
    2) Shut down the system. Don't let it reboot after doing the rearm.
    From now on, you'll be treating the drive like a data drive,
    on another computer. At least, until you think you've made a
    good copy of the drive.
    3) Connect the RAID drive and an empty drive, to a machine that
    properly recognizes the RAID drive as a data drive. Then,
    copy the drive to the empty drive. You could use the current machine,
    as long as you have an OS to use to do the copying.

    My assumption here, is there's something wrong near the beginning
    of the disk, such as the metadata is located near the beginning, instead
    of near the end.

    I can give you an example. I had a board with Intel and Promise controllers.
    A drive was primed on the Promise controller. The Promise controller
    places metadata on the drive (like you'd find on a RAID). When I would
    move the Promise drive to the Intel controller, the first partition would
    "disappear". And it would promptly "reappear", when connected to the
    Promise controller. That tells me something is "offset", and the
    data needs to be copied off, using an environment that understands
    the Promise format.

    To fix that, you'd need to copy the data off it. For example, I could
    have used a USB enclosure, put the empty drive in that, and copied
    the partitions off the Promise drive, using Partition Magic (one partition
    at a time). Or used Linux GParted (seeing as the boot drive is broken,
    a Linux LiveCD might be in order). The empty drive would end up with an MBR,
    with partition entries created by Partition Magic, and then I'd need to do the
    equivalent of a "fixmbr" to put the MBR boot code back. The Windows 7 installer
    DVD can be used to do that.

    "Under Windows Vista and Windows 7, the Recovery Environment can be used
    to write new MBR code using the bootrec /FixMbr command."

    When the partitions are copied, the partition boot sector should have got
    copied as well, so that wouldn't need to be repaired.

    Anyway, because I'm "copying", my experiment can't break anything, and
    eventually I might get the copy placed on the empty drive, to boot.
    Since the driver rearm procedure was followed, just before the source
    system was shut down, the next boot of that disk, after it's been
    repaired (like "fixmbr" equiv), it should be able to run in IDE or
    AHCI or whatever.

    And the reason I'd do it that way, is I'm stubborn :)

    Paul, May 19, 2012
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