HP Array Configuration Utility User Guide (416146-001, January 2006)

Scripting in ACU 36
Read:write
ratio
RA4x00 with
16MB cache
RA4x00 with
48MB cache
All other controllers with
battery-backed cache
All other controllers
without battery-backed
cache
70:30 Y Y -- --
60:40 Y Y -- --
50:50 Y Y Y --
40:60 -- Y -- --
30:70 -- Y -- --
25:75 -- Y Y --
0:50* Y -- -- --
0:75* -- Y -- --
0:100 -- -- Y --
* The cache ratio percentages do not total 100 in these cases because the additional 16-MB or 48-MB cache
modules are not used. Only the battery-backed write cache is used.
RebuildPriority, ExpandPriority
This option has three possible values: Low, Medium, and High. The default value for an unconfigured
controller is Low.
SurfaceScanDelay
Enter a number between 1 and 30 to specify the duration of the surface scan delay in seconds.
SSPState
There are two settings for this option: Enable and Disable. If you do not specify a value for the SSP State,
the existing setting remains unchanged.
NOTE: The SSPState option is valid only for controllers that enable SSP on a controller basis, such as the
MSA1000 or the Smart Array Cluster Storage controllers. RA4x00 controllers support SSP that is enabled on
a logical drive basis, and use the LogicalDriveSSPState option ("LogicalDriveSSPState" on page 39) instead.
If you enable SSP, you must also specify an adapter for one or more logical drives by using the
SSPAdaptersWithAccess option ("SSPAdaptersWithAccess" on page 39). Otherwise, SSP is automatically
disabled.
PreferredPathMode
The setting that you select for this option determines how the preferred I/O path to a particular logical
drive is set for a redundant array controller that is in an active/active configuration.
Not all controllers support this feature, and controllers in an active/standby configuration disregard this
option.
• Auto is the default setting for new configurations. In this case, the storage system automatically
selects the I/O path from the redundant controller to the logical drive and dynamically load
balances all paths.
• Manual enables you to assign the logical drive to a specific redundant controller. If you select this
setting, use the PreferredPath (on page 39) command to specify the path.
If you are reconfiguring a controller and do not specify a setting for this option, the existing setting
remains unchanged.