HP P2000 G3 Cli Reference Manual page 198

Cache Write Policy
If a volume is specified, its cache write policy:
• write-back: Write-back caching does not wait for data to be completely written to disk before
signaling the host that the write is complete. This is the default and preferred setting for a
fault-tolerant environment because it improves the performance of write operations and
throughput.
• write-through: Write-through caching significantly impacts performance by waiting for data
to be completely written to disk before signaling the host that the write is complete. Use this
setting only when operating in an environment with low or no fault tolerance.
Cache Optimization
If a volume is specified, its cache optimization mode:
• standard: Optimizes cache for both sequential and random reads. Appropriate for
applications that read and write small files in random order, such as transaction-based and
database update applications. This is the default.
Read Ahead Size
If a volume is specified, its read-ahead cache setting:
• Disabled: Read-ahead caching is disabled.
• Default: One chunk for the first access in a sequential read and one stripe for all subsequent
accesses.
• Maximum: Maximum read-ahead size calculated by the controller.
• 64 KB, 128 KB, 256 KB, 512 KB, 1 MB, 2 MB, 4 MB, 8 MB, 16 MB, or 32 MB: Size selected
by a user.
Example Show the cache parameters for the system and for volume V1:
# show cache-parameters V1
System Cache Parameters
-----------------------
Operation Mode: Active-Active ULP
Controller A Cache Parameters
-----------------------------
Write Back Status: Enabled
CompactFlash Status: Installed
Cache Flush: Enabled
Controller B Cache Parameters
-----------------------------
Write Back Status: Enabled
CompactFlash Status: Installed
Cache Flush: Enabled
Volume Cache Parameters
-----------------------
Serial Number: SN
Name: V1
Cache Write Policy: write-back
Cache Optimization: standard
Read Ahead Size: Default
Success: Command completed successfully. (2012-01-18 14:31:19)
Basetypes • cache-settings
• cache-parameter
• status
198 Alphabetical list of commands