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cannot boot with raid 5 disks RRS feed

  • Question

  • Hi Dear,

    I am having three raid 5 ( three disks) on raid card, there is no problem in the raid,

    but unfortunately it cannot able to boot the system.

    is the problem somewhere in bios or in HDD's?

    Kindly please suggest me .

    Saturday, April 7, 2012 9:34 AM

Answers

  • The issue is that when the BIOS starts to boot windows those RAID drivers aren't loaded yet - so it's up to the chipset itself to understand how to read the boot sectors from the RAID volume. This is fairly simple for RAID 0, 1 or RAID 10 because the boot blocks are easy to locate on one or more of the drives, so the limited capabilities of the ICH chipset are able to handle it. 

    RAID 5 is different because if there is a failed disk in the RAID set then the data has to be recreated by reading the other drives and performing parity calculations in order to recover the information. I strongly suspect the ICH chipset isn't capable of doing this on it's own, so that would mean it couldn't be used for a RAID 5 boot device.

    Your system config please.

    • Proposed as answer by DarienHawk67 Saturday, April 7, 2012 9:45 PM
    • Marked as answer by Nicholas Li Friday, April 13, 2012 5:22 AM
    Saturday, April 7, 2012 9:58 AM
  • (Dear?)

    This isn't an area of great familarity to me, but:

    What's the capacity of your RAID 5 array?

    I believe that Windows cannot boot from a drive (or array) larger than 2GB, unless the system's motherboard supports EFI, and the disk (array) is configured with a GPT rather than a MBR.

    http://en.wikipedia.org/wiki/GPT_Disk


    • Edited by bobkn Saturday, April 7, 2012 4:28 PM
    • Marked as answer by Nicholas Li Friday, April 13, 2012 5:22 AM
    Saturday, April 7, 2012 4:28 PM
  • For a desktop system, disk failures are relatively rare, so a RAID 5 array shouldn't be an issue. The main issue is that the card isn't well integrated into the BIOS, so rather than presenting the system a volume that displays independently of the underlying storage redundancy, this controller seems to be relying on the operating system to know how to access the array...
    • Marked as answer by Nicholas Li Friday, April 13, 2012 5:23 AM
    Monday, April 9, 2012 4:44 AM

All replies

  • The issue is that when the BIOS starts to boot windows those RAID drivers aren't loaded yet - so it's up to the chipset itself to understand how to read the boot sectors from the RAID volume. This is fairly simple for RAID 0, 1 or RAID 10 because the boot blocks are easy to locate on one or more of the drives, so the limited capabilities of the ICH chipset are able to handle it. 

    RAID 5 is different because if there is a failed disk in the RAID set then the data has to be recreated by reading the other drives and performing parity calculations in order to recover the information. I strongly suspect the ICH chipset isn't capable of doing this on it's own, so that would mean it couldn't be used for a RAID 5 boot device.

    Your system config please.

    • Proposed as answer by DarienHawk67 Saturday, April 7, 2012 9:45 PM
    • Marked as answer by Nicholas Li Friday, April 13, 2012 5:22 AM
    Saturday, April 7, 2012 9:58 AM
  • (Dear?)

    This isn't an area of great familarity to me, but:

    What's the capacity of your RAID 5 array?

    I believe that Windows cannot boot from a drive (or array) larger than 2GB, unless the system's motherboard supports EFI, and the disk (array) is configured with a GPT rather than a MBR.

    http://en.wikipedia.org/wiki/GPT_Disk


    • Edited by bobkn Saturday, April 7, 2012 4:28 PM
    • Marked as answer by Nicholas Li Friday, April 13, 2012 5:22 AM
    Saturday, April 7, 2012 4:28 PM
  • I do not recommend RAID5 for a desktop, that is meant for a server where storage is at issue. RAID5 is also obsolete, RAID6 is more fault tolerant.

    I assume the RAID card has a BIOS that can cope with MBR limitations by allowing GPT booting


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    Basharath is using 3 disks.

    If memory serves, the capacity of a RAID 6 array would be (n-2) times that of a single disk. If n is 3, that would be a rather unusual array. (Capacity the same as 1 disk.)

    Monday, April 9, 2012 3:02 AM
  • For a desktop system, disk failures are relatively rare, so a RAID 5 array shouldn't be an issue. The main issue is that the card isn't well integrated into the BIOS, so rather than presenting the system a volume that displays independently of the underlying storage redundancy, this controller seems to be relying on the operating system to know how to access the array...
    • Marked as answer by Nicholas Li Friday, April 13, 2012 5:23 AM
    Monday, April 9, 2012 4:44 AM