If for any reason your primary operating system drive fails or goes
off-line while in a raid level-1 mirrored configuration, Windows NT
continues to run from the mirrored drive and flags the registry hives on
the current drive to reflect the broken mirror.
If you perform a normal shutdown at this point, revive the primary
operating system drive, and then perform a normal boot, the STOP:0x58
FTDISK_INTERNAL_ERROR error message appears.
Windows NT uses this protection mechanism because processing continued on
the shadow drive while the primary drive was off-line. Any data saved
to the shadowed drive would be lost if you were permitted to boot from the
primary drive again.
To guard against data loss and fully recover from the STOP error message
above:
- Run Disk Administrator. Notice that the primary operating system
disk partition is red, indicating that the mirror is broken. Notice
that the primary drive will show the drive letter "C:". It must be
changed to a new drive letter by breaking the mirror.
- Using Disk Administrator, officially break the mirror:
a. Highlight the partition.
b. Select Fault Tolerance and choose Break Mirror.
c. On the Partition menu, click Commit Changes Now.
NOTE: If a message appears indicating that the mirror set cannot
be locked and the system will need to be restarted in order to
complete the breakage, choose YES.
NOTE: Although the data on the primary disk is older than the data on
the secondary disk you have the option at this point to boot to the
primary disk using the older data and re-establishing the mirror.
Simply reverse the drive assignments in the following steps. This
also may allow you to over come the problem listed in the warning
listed in step 4.
- Once the mirror is successfully broken and you have two separate
partitions, do a tape backup of the mirrored drive you are currently
running from. This is the most current data you have and contains all
the information saved since the primary operating system drive failed.
NOTE: This is only a precautionary step because you are no longer in a
fault tolerant configuration. You can skip this step if you are under
time constraints, but Microsoft does not recommend you do so if
critical data is involved.
WARNING: There may be cases when disk mirroring with unlike drives or
controller types could cause the mirrored partition to be larger
than the original master partition. If the two partitions are not the
exact same size in Disk Administrator, do not follow this procedure
any further because you will not be able to re-mirror to a smaller
partition size later. Instead, restore from the backup tape you made in
this step to the primary system partition. Proceed to Step 9 after
completing the restore.
- Mark active the primary partition on the secondary drive. A reboot
may be required. Complete this step before continuing.
Delete the primary drive partition so you can re-mirror the current
operating system back to the primary drive:
a. Select the primary drive partition
b. On the Partition menu, click Delete.
c. On the Partition menu, click Commit Changes Now.
NOTE: You may need to move the paging file to another drive and reboot
before you are allowed to delete the partition.
NOTE: If the entire primary C drive was mirrored and does not
contain another primary partition to mark active, Disk Administrator
will not allow you to delete the active partition. In this situation,
moving the drive to a secondary non-bootable drive position (SCSI
I.D greater than 0 or slave IDE drive) should allow you to delete the
primary partition. If this is not possible, you can use Norton
Utilities Disk Editor (Diskedit.exe) to remove the boot flag from the
partition table manually.
- Re-mirror the drives:
a. Select the current operating system drive partition and while
holding down the CTRL key.
b. Select the free space created in Step 5.
c. On the Fault Tolerance menu click Establish Mirror.
d. On the Partition menu click Commit Changes Now.
You can verify the mirror is established by either exiting and
re-starting Disk administrator to check on the status of the mirror, or
look for an Event:19 from Source:FTDISK in the system event log
indicating that the mirror initialization or synchronization is
complete.
- Once this mirror is successfully established, you have a snapshot of
the most current data onto the primary disk. Unfortunately you cannot
reboot from the primary disk at this time because it is only a mirror.
You cannot boot from a mirror while the master is active. You must re-
break the mirror again by following Step 3 above.
- Once the mirror is broken, mark the partition active if it is the
primary boot partition.
- Perform a normal shutdown and reboot from your primary operating
system drive. Once Windows NT is running, delete the partition and
then re-establish the mirror to regain your fault tolerant RAID-1
configuration.
An quick alternative way to recover is outlined below, but may result
in possible data loss. Use at your own risk.