Compaq HSZ80 manual 134CLI Commands, Writebackcache Default

5–134CLI Commands

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. 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. 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 the controller’s write-back caching. WRITEBACK_CACHE cannot be enabled on units with an underlying DT_SUPPORT mirrorset container.

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.

NOTE: The controller may take up to 5 minutes to flush data contained within the write-back cache when you specify the NOWRITEBACK_CACHE switch.