User`s guide

SET OTHER_CONTROLLER
SET OTHER_CONTROLLER
Changes the other controller’s parameters (in a dual-redundant configuration,
the controller that the maintenance terminal is not connected to, or the controller
that is not the target of the DUP connection.
Format
SET OTHER_CONTROLLER
Description
The SET OTHER_CONTROLLER command allows you to modify the controller
parameters of the other controller in a dual-redundant configuration.
Qualifiers for HSD Controllers
CACHE_FLUSH_TIMER= n
CACHE_FLUSH_TIMER=DEFAULT
Specifies how many seconds (1–65535) of idle time may elapse before the write-
back cache flushes its entire contents to disk. After the specified time, the
write-back cache flushes its contents to disk to ensure data integrity. Whenever
a change is made to the CACHE_FLUSH_TIMER parameter, the controller must
be restarted for the change to take effect.
CACHE_POLICY=A (Default)
CACHE_POLICY=B
Allows selection of the write-back cache battery policy used by the controller.
The policy affects the availability of RAIDsets and mirrorsets when the battery
condition is low during controller intialization.
Changing this policy on one controller in a dual-redundant controller
configuration automatically changes it on the other controller. The parameter
change takes effect immediately.
The CACHE_POLICY setting affects RAIDsets and mirrorsets as follows:
• If the CACHE_POLICY on the controller is set to A and the batteries are low
when the controller initializes, any RAIDset or mirrorset that does not have
access to good batteries is made inoperative.
• If the CACHE_POLICY on the controller is set to B and the batteries are low
when the controller initializes, any RAIDset or mirrorset that does not have
access to good batteries is accessed in write-through (read cache) mode.
Regardless of the CACHE_POLICY setting, a low or bad battery affects controller
operation:
• Stripesets and disk-based units with write-back caching enabled are accessed
in write-through (read cache) mode, as long as unwritten cache data has not
been lost.
• HSJ- and HSD-based RAIDsets and mirrorsets fail over to the companion
cache in a dual-redundant configuration, provided the other cache’s batteries
are fully charged. RAIDsets and mirrorsets on HSZ and nonredundant
controller systems will not fail over.
B–66 Command Line Interpreter