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

Configuring Magnetic Disks

SCF Reference Manual for the Storage Subsystem—529937-008

6-15

Remirroring Disks Online

You can perform these tasks without stopping the entire disk volume:

•

Change the disk configuration from an unmirrored configuration to a mirrored

configuration

•

Relocate both the mirror disk and primary disk to new slots

•

Unmirror a disk volume

•

Switch the roles of the two disks of a mirror disk volume

Throughout the performance of these tasks, a primary disk drive is always available to

applications. Thus, applications need not be taken out of service. For an example of

disk relocation, see Example of Online Disk Remirroring on page 6-17. Before you

consult this example, read these considerations.

Considerations for ALTER DISK, MIRRORLOCATION and

Online Disk Remirroring

•

You cannot specify the attribute MIRRORLOCATION and the attribute

SWAPMIRROR in the same ALTER DISK command.

•

You can issue this command when all paths to the primary disk drive are in a

STARTED state. However, the paths to the mirror disk drive must be in a

STOPPED state.

•

Example of Online Disk Remirroring on page 6-17 deals with internal disks in a

NonStop S-series system enclosure. To remirror other types of disks, you need to

specify additional attributes whenever MIRRORLOCATION is specified:

•

For M8xxx disks in an FCDM, you must specify MIRRORLOCATION,

MIRRORDEVICEID, and MIRRORSAC.

For the backup path, specify MBACKUPLOCATION and MBACKUPSAC.

•

For model 45xx disks in a modular disk subsystem, you must specify

MIRRORLOCATION, MIRRORDEVICEID, and MIRRORSAC.

For the backup path, specify MBACKUPLOCATION and MBACKUPSAC.

•

For ESS disks, you must specify MIRRORLOCATION, MIRRORSAC,

MIRRORPORTNAME, and MIRRORLUN.

For the backup path, specify MBACKUPLOCATION and MBACKUPSAC, and

MBACKUPPORTNAME.