SCF Reference Manual for the Storage Subsystem (G06.28+, H06.05+, J06.03+)

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.
• Effective with the H06.23/J06.12 RVU, you can use the attribute NOSTART with the ALTER
DISK command to specify that the configured mirror disk should not be started.
• “Example of Online Disk Remirroring” (page 81) 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.
Considerations for ALTER DISK, SWAPMIRROR, and Online Disk Remirroring
• The SWAPMIRROR attribute causes the two disk drives of a mirrored disk volume to switch
roles:
◦ The primary disk drive becomes the mirror disk drive.
◦ The mirror disk drive becomes the primary disk drive.
• To delete the paths to a primary disk drive when you perform online disk remirroring, you
must first use an ALTER DISK, SWAPMIRROR command so that the primary disk drive becomes
the mirror disk drive. You cannot DELETE the paths to a disk drive that is currently serving as
the primary disk drive.
• For the ALTER DISK, SWAPMIRROR command to work:
The disk volume must be mirrored.◦
◦ Both disk drives must have the same number of paths; that is, both disks either have, or
do not have, backup paths.
• You cannot specify both the attribute SWAPMIRROR and the attribute MIRRORLOCATION in
the same ALTER DISK command.
• The SWAPMIRROR command is allowed only when the disk paths are in one of these
combinations of states:
-MB-M-B-P
STARTEDSTARTEDSTARTEDSTARTED
STOPPEDSTARTEDSTOPPEDSTARTED
STARTEDSTOPPEDSTARTEDSTOPPED
STARTEDSTARTEDSTOPPEDSTOPPED
STOPPEDSTOPPEDSTARTEDSTARTED
80 Configuring Disks