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March 05, 1999 12:00 AM

Why can't I use the other disk of the mirror set to boot Windows NT?

Windows IT Pro
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A. When you create a mirror disk, you automatically create the partition. However, you don’t automatically update the Master Boot Record (MBR) of the disk with the Windows NT boot loader.

To install the NT boot loader, first partition and use Disk Administrator to format the drive, which writes the MBR to the shadow disk. You then delete this partition and continue creating the mirror.

If you already have a mirror disk that you need to boot from and don’t want to use a modified NT boot disk (see Q. How do I create an NT Boot Disk? for details), you can use the repair process to write the MBR record to the shadow disk. To do so, complete the following steps:

  1. Use the three NT installation disks to boot the machine.
  2. After you run the first two disks, the installation program gives you options to choose from. Select R for repair.
  3. Clear the checkboxes for all options except Inspect Boot Sector, and continue.
  4. Press Enter to detect hardware, and insert the third disk.
  5. The repair procedure will ask if you have an Emergency Repair Disk (ERD). Choose Yes, and insert the ERD.
  6. The machine will reboot, and the shadow disk will include the MBR record.

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Comments
  • John Nguri
    8 years ago
    Feb 23, 2004

    excellent job! please confirm:
    Say i have two drives first drive 0 second drive 1
    OS Windows 2000 sp 4
    drive 0 has two partitions C and D these two i mirror to drive 1 respectively, i break the mirror but i want to not only boot from drive 1 now - the new drive but to also read and access and continue working on an application say MS exchange 2000, if i follow this same process will my application run?

  • Grahame Richards
    9 years ago
    Jan 20, 2003

    We tried the formula - many thanks. We attached the mirrored drive as a master to the primary IDE channel
    Inserted FD1, then FD2 - detected the CDRom but not the drive. Followed instructions to the letter
    It never asked for ERD
    "Setup cannot continue"

    cheers

  • David Nelson
    11 years ago
    Feb 28, 2001

    Brilliant! So simple when you think about it! But I've been trying to work out why the shadow disk wouldn't boot for ages. We use Mirroring on our PDC and then break the mirror to provide an identical backup disk. Up 'till now I've only been able to boot the shadow disk with a boot disk. The Microsoft instructions (and others) about how to do this simply don't work!! (Surprise surprise!!)

    Thanks

    David Nelson
    Network Manager
    Wangaratta High School

  • Brandon Shirey
    12 years ago
    Nov 20, 2000

    Step #2 is incorrect. It is after Disk 3 that it prompts you for repair. And I don't exactly understand the Question of this article. "boot using on the mirror.." Boot using what?

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