SCF Reference Manual for the Storage Subsystem (G06.27+, H06.04+)

Managing Magnetic Disks
SCF Reference Manual for the Storage Subsystem—529937-008
7-4
Reviving a Mirrored Disk
4. Confirm that the disk has started:
-> STATUS $DISK00
5. If the START DISK command fails, see the information on troubleshooting disk
drives in the Service and Support Library of the NonStop Technical Library (NTL).
Reviving a Mirrored Disk
The START DISK Command (page 14-109) makes a stopped disk accessible to user
processes and revives the second half of a mirrored volume.
Use this procedure if you have stopped one half of a mirrored volume and need to
synchronize the two halves when restarting the disk. This situation can occur if:
•
You do something that affects only one disk of a mirrored volume. For an example,
see Replacing the Bootstrap Program (page 7-19).
•
You back up disk files by replacing the mirror drive with another drive instead of
using BACKUP and RESTORE.
•
You are Swapping Processors for a Disk (page 7-24).
•
One half of a mirrored pair experiences a physical media failure, and you have to
stop and remove it.
Considerations When Reviving a Mirrored Volume
•
Do not stop the revive operation by issuing a STOP DISK command unless you
want to force the next revive operation to restart from the beginning. See Stopping
a Revive Operation on page 7-7.
•
If a nonfatal error occurs, the revive operation does not proceed but stalls or goes
into a loop. The START DISK command continues to retry at the current address
until either the revive operation is successful or the revive operation is suspended
or stopped. For more details, see Stopping a Revive Operation
on page 7-7.
•
When SCF must revive the information on the volume before starting the volume,
the revive operation can seriously affect system performance, especially for users
of the volume being revived. You can use the RESET DISK command to
temporarily suspend the revive operation when needed. See Temporarily Stopping
a Revive Operation on page 7-8.
STORAGE - Status DISK \COMM.$DISK00
LDev Primary Backup Mirror MirrorBackup Primary Backup
PID PID
212 *STARTED STARTED *STARTED STARTED 9,262 8,271