SQL/MX 3.1 Installation and Management Guide (H06.23+, J06.12+)

Performing Recovery Operations
HP NonStop SQL/MX Release 3.1 Installation and Management Guide—663852-001
12-38
ALTER DISK, ALTNAME and ALTER DISK,
VOLNAME
store production SQL/MX database files. Use the drive for a test database or for
temporary space for sort files. You must ensure that you can make the volume inactive
and revive the drive back to its original mirrored configuration with no effect on the
original database.
Use the ABORT DISK command on a volume to put a particular volume out of
operation. You can later use the START DISK command to put the same disk back into
operation. See START DISK and STOP DISK
on page 12-40. Inconsistency is unlikely
if the disk brought up is identical to the disk brought down. Always perform a
STOPOPENS DISK on the volume and a CONTROL DISK, REFRESH on the volume
to ensure valid file labels before you make the volume inactive.
The only exception to the preceding rule is if the entire database has been consistently
brought down as a unit. For example, suppose that you use ABORT DISK to bring
down all the backup volumes of the mirrored pairs containing SQL/MX objects in a
consistent state. The other mirrored set continues the active database, but the inactive
mirrors also contain a set of consistent SQL/MX objects.
ALTER DISK, ALTNAME and ALTER DISK, VOLNAME
If a volume is renamed inadvertently, reissue the command to rename the volume to its
previous name. If this is not possible, recover the volume only if all the objects on the
renamed volume are described in catalogs on the same volume. If this is the case, use
BACKUP and RESTORE to back up the volume:
1. Identify all the SQL/MX objects to be renamed and all dependencies. Produce
hard-copy reports containing this information.
2. Create an EDIT file containing CREATE CATALOG and ALTER TABLE statements
to re-create the catalogs and reset the security of the catalog tables.
3. Back up the volume by using a file-mode BACKUP command.
4. Use ALTER DISK, ALTNAME to rename the disk. You might first want to label the
disk with ALTER DISK, LABEL to clear the old files.
To restore files:
1. Re-create the catalogs on the renamed volume by using the file created in Step 2
as the input file for the MXCI OBEY command.
Caution. You cannot use ABORT DISK on a volume and replace the volume with an earlier
version of that same volume without causing inconsistencies in the database.
Caution. ALTER DISK, ALTNAME and ALTER DISK, VOLUME are extremely dangerous
commands because they 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, and then perform a STOP DISK to make the volume inactive.
The ALTER DISK operation renames the files on a volume, but SQL/MX metadata and file
labels still contain the old names. Use it only on disks that contain SQL/MX objects. ALTER
DISK should be used only for volumes that do not contain SQL/MX objects.