User`s guide

SET unit-number
Note
The PREFERRED_PATH and NOPREFERRED_PATH qualifiers are
valid for HSJ and HSD controllers only. The preferred path for HSZ
controllers is determined by the unit number (the target portion of the
unit number–the hundreds place) specified on the ADD UNIT command.
Specifies the preferred controller that the unit should be accessed through
(PREFERRED_PATH=) or whether the unit may be accessed through either
controller (NOPREFERRED_PATH).
The preferred path qualifier is used only if both controllers are running in a
dual-redundant configuration. If one controller fails, then all the devices will be
made accessible through the remaining controller, ignoring the preferred path
setting.
When the failed controller is restarted, the drives automatically return to the
controller specified by the preferred path qualifier.
Note
The PREFERRED_PATH qualifier may be specified on a single controller,
however, the qualifier will not take effect until a second controller is
added and the two controllers are configured for dual-redundancy. The
second controller will inherit any PREFERRED_PATH settings, and the
two controllers will operate using the preset PREFERRED_PATH options.
RUN (Default)
NORUN
Enables and disables a unit’s availibility to the host. When RUN (default) is
specified, the devices that make up the unit will be spun up and the unit will be
made available to the host. If NORUN is specified, the devices that make up the
unit will still be spun up, but the unit will not be made available to the host.
WRITE_PROTECT
NOWRITE_PROTECT (Default)
Enables and disables write protection of the unit.
Note
Writes may still be performed to a write-protected RAIDset to satisfy a
reconstruct pass or to reconstruct a newly replaced member. However,
write protect will disable the writing of any new data.
WRITEBACK_CACHE
NOWRITEBACK_CACHE (Default)
Enables and disables the controller’s write-back cache on this unit.
B–88 Command Line Interpreter