HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Command Line Interface Reference Guide (EK-G80CL-RA. C01, March 2005)

CLI Command Descriptions
95HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software
Command Line Interface Reference Guide
Read-ahead caching improves host application performance since the data is
read from the controller cache instead of disk. Read-ahead caching is the
default for units.
If you are adding a unit that is not expected to get sequential I/O requests, use
the NOREADAHEAD_CACHE switch for the unit.
RUN (default)
NORUN
Controls the unit availability to the host:
■ Specify RUN to make a unit available to the host.
■ Specify NORUN to make a unit unavailable to the host and to cause any
data in cache to be flushed to one or more drives. NORUN spins down all
the disks used in the unit. The drives comprising the unit spin down after
the data is completely flushed.
Note: Do not specify the RUN or NORUN switches for partitions.
WRITE_PROTECT
NOWRITE_PROTECT (default)
Specifies whether data contained on the selected unit can be overwritten:
■ Specify WRITE_PROTECT to prevent host write operations to the unit.
The controller can still write to a write-protected RAIDset to satisfy a
reconstruct pass or to reconstruct a newly replaced member. Additionally,
metadata, reconstruct, and copy writes are still allowed to RAIDsets and
mirrorsets.
■ Specify NOWRITE_PROTECT to allow the host to write data to the unit.
This allows the controller to overwrite existing data.
WRITEBACK_CACHE
NOWRITEBACK_CACHE
Enables or disables the writeback data caching function of the controller. The
controller writeback caching feature improves write performance.