HP Array Controller HSG V8.7 Software - Manual (Page 377)

CLI Commands B–105
ALLOCATION_CLASS
Allocation class is a unique identification number assigned to the
controller pair under certain operating systems. In Digital open VMS,
this is a 2-byte number; for Digital UNIX, it is a 4-byte number. It is
reported in response to the SCSI inquiry command and is the same for
all units connected to one or both controllers. It allows the user to place
a unique number in the allocation class value (n). The allocation class
value allows the host to identify the controllers that are a matched dual-
redundant pair. This number should be unique for every pair of dual-
redundant controllers in the cluster.
Note This value must not be zero (default) in dual-redundant
configurations in host systems that implement allocation class. A zero
value in this configuration causes the operating system to disable
failover between the controller pair. Some operating systems do not
implement allocation class, in which case the default of zero has no
meaning.
CACHE_FLUSH_TIMER=n
CACHE_FLUSH_TIMER=10 (Default)
Specifies how many seconds (1–65535) of idle time may elapse before
the write-back cache flushes its entire contents to a given device or
RAIDset. The default setting is 10 seconds. When changed, the new
value entered for this switch takes effect immediately.
CACHE_UPS
NOCACHE_UPS (Default)
Specifies whether the controller should perform regular battery
condition checks. When changed, you must restart both controllers in
order for the new setting to take effect.
Specify CACHE_UPS if your storage subsystem power is supported by
an uninterruptable power supply (UPS). The controller does not check
the condition of the cache batteries and ignores the battery’s state. This
causes RAIDsets and mirrorsets to always be available, regardless of
the condition of the cache batteries.
Caution Setting CACHE_UPS without having a UPS or similar
backup system in place may result in data loss if power is interrupted.