HP Array Controller HSG V8.7 Software - Manual (Page 413)

CLI Commands B–141
unit. The drives making up the unit spin down after the data has been
completely flushed.
Note Do not specify the RUN and NORUN switches for partitioned
units.
WRITE_PROTECT
NOWRITE_PROTECT (Default)
Assigns to the unit’s a write-protect policy.
Specify WRITE_PROTECT to prevent host write operations to the unit.
However, the controller may still write to a write-protected RAIDset to
satisfy a reconstruct pass or to reconstruct a newly replaced member.
However, 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.
NOWRITE_PROTECT is the default for transportable disks.
WRITEBACK_CACHE (Default)
NOWRITEBACK_CACHE
Enable or disable the write-back data caching function of the controller.
The controller’s write-back caching feature improves write
performance. NOWRITEBACK_CACHE is the default on transportable
disks.
Specify WRITEBACK_CACHE for all new RAIDsets, mirrorsets, and
units you want to take advantage of write-back caching.
Specify NOWRITEBACK_CACHE for units you want to receive data
directly from the host without being cached.
Caution Though there is built-in redundancy to protect data contained
in cache, allowing data to be written to write-back cache may result in
the loss of data if the controller fails.