198 Alphabetical list of commands
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
Summary of Contents for P2000 G3
Page 1: ...HP P2000 G3 MSA System CLI Reference Guide Part number 500912 009 First edition February 2014 ...
Page 14: ...14 About this guide ...
Page 30: ...30 Categorical list of commands ...
Page 199: ...HP P2000 G3 MSA System CLI Reference Guide 199 See also set cache parameters show volumes ...
Page 294: ...294 Alphabetical list of commands See also set volume set vdisk ...
Page 498: ...498 XML API basetype properties PROPERTY name mrc version type uint8 0 PROPERTY OBJECT ...
Page 524: ...524 Glossary ...
Page 532: ...532 Index ...