HP Surestore Disk Array 12h and FC60 - Manual (Page 300)

300 Managing the Disk Array Using Array Manager 60
see Table 31 on page 250 for details on what performance impact altering these settings
may have.
Setting Cache Page Size
Data caching improves disk array performance by storing data temporarily in cache
memory. The cache page size can be set to either 4
K
bytes or 16
K
bytes. The default page
size is 4 Kbytes. The page size is set for both controllers in the disk array.
To set cache page size, type:
ammgr -p {4|16} <ArrayID>
Command Example
The following example sets the cache page size to 16
K
bytes on disk array rack_1:
ammgr -p 16 rack_1
Setting the Cache Flush Threshold
The cache flush threshold sets the level at which the disk array begins flushing (writing)
cache content to the disks. Cache will be flushed until the cache flush limit value is
reached. The default value for this setting is 80%. The cache flush threshold can be set
independently for each controller.
To set cache flush threshold, type:
ammgr -T <cntrlrID>:<percent> <ArrayID>
• percent indicates the percentage of cache memory that must be full before flushing
begins. For example, if set to 80%, cache flushing will begin when 80% of cache memory
is full.
Command Example
The following example sets the cache flush threshold to 80% for controller A on disk array
0000005EBD20:
ammgr -T A:80 0000005EBD20