SQL/MX 2.x Installation and Management Guide (H06.10+, J06.03+)

Performing Recovery Operations
HP NonStop SQL/MX Installation and Management Guide—544536-007
12-39
ALTER DISK, LABEL
ALTER DISK, LABEL
You can safely use ALTER DISK, LABEL on disk volumes with SQL/MX objects in
these situations:
•
To label a disk that has been destroyed and has completely corrupt data
•
To label all the disks on a node and recover the database with a complete restore
•
To label a disk following repair or replacement if a volume with SQL/MX objects
has a catastrophic failure and no mirrored volume is available. In this situation, you
should label the disk with its previous name.
To recover the volume with the ALTER DISK, LABEL command:
1. Retrieve the tables by using the latest TMF online dumps and TMF file recovery. To
initiate a file recovery of all files on $VOL, enter this command through one of the
TMF interfaces (this example uses TMFCOM):
RECOVER FILES $VOL.*.*, FROMARCHIVE
2. Check that dependent objects residing on other volumes have also been recovered
and re-create objects as necessary.
3. Verify the database by using the mxtool VERIFY utility. For command syntax and
operating guidelines, see the SQL/MX Reference Manual.
4. Make new TMF online dumps of SQL/MX objects that reside on the volume. If the
entire object was re-created, take dumps of the entire object even if one or more
partitions reside on different volumes.
INITIALIZE DISK
The INITIALIZE DISK command prepares the disk for use on the system. This
command deletes any existing files on the volume, deletes the log of spared sectors,
initializes the customer engineer sector and the spare-tracks table, and optionally
labels the disk. To recover an initialized disk volume, follow the steps in ALTER DISK,
LABEL on page 12-39.
START DISK and STOP DISK
Use the STOP DISK command on a mirrored volume pair to make one half of the pair
inactive. The active disk drive of the mirrored pair continues to maintain the current
database, without the protection of mirroring.
Caution. ALTER DISK, LABEL use is extremely dangerous because it can corrupt a database.
Before using an ALTER DISK command, perform a STOPOPENS DISK and a CONTROL
DISK, REFRESH on the volume to ensure valid file labels. Then perform a STOP DISK to
make the volume inactive. Do not use this command on disks containing SQL/MX objects, with
a few exceptions.