HP Array Controller HSG V8.7 Software - Manual (Page 344)

B–72 HSG80 User’s Guide
Switches
CAPACITY=
CYLINDERS=
HEADS=
SECTORS_PER_TRACK=
CAPACITY may be specified 1 to the maximum container size (in
blocks); CYLINDERS may be specified 1 to16,777,215; HEADS may
be specified 1 to 255; and SECTORS_PER_TRACK may be specified
1 to 255.
Note These are used to set the SCSI parameters reported to the host.
They should not be used unless there is a compatibility problem with
the existing defaults.
The geometry parameter switches for the INITIALIZE command are
ignored when you create partitions. The parameters supplied with the
CREATE_PARTITION command are used by the unit.
CHUNKSIZE=DEFAULT (Default)
CHUNKSIZE=n
Specifies the block chunk size to be used for RAIDsets and stripesets.
You can specify the chunk block size by entering CHUNKSIZE=n or
allow the controller to determine the optimal chunk block size by
entering CHUNKSIZE=DEFAULT.
Note The CHUNKSIZE switch is only valid with stripesets and
raidsets.
The default chunk size for storagesets with less than nine members is
256 blocks, or 128 kilobytes (K). The default chunk size for storagesets
with more than nine members is 128 blocks, or 64K. The default values
provide optimal storageset performance for a wide variety of
applications. A chunk size less than 128 blocks (64K) is not
recommended.
Tip Accept the default chunk size setting for most applications. Do
not change the default setting unless you are fully aware of the impact
to the storageset’s performance.