Software Instruction Manual

Toolkit utilities 47
ReadCache, WriteCache
Enter a number between 0 and 100 to specify the percentage of cache that is to be allocated to drive
reads or writes. The default value for both options is 50.
The allowable cache ratios depend on the controller model and whether it has battery-backed write
cache, as described in the following table.
A "+" indicates that the specified cache ratio is allowed for that type of controller, while a "–" indicates
that the ratio is not allowed.
Read:write
ratio
RA4x00
with 16MB
cache
RA4x00
with 48MB
cache
All other controllers
with battery-backed
write cache
All other controllers
without battery-backed
write cache
100:0 + + + +
90:10 + + – –
80:20 + + – –
75:25 – – + –
70:30 + + – –
60:40 + + – –
50:50 + + + –
40:60 – + – –
30:70 – + – –
25:75 – + + –
0:50* + – – –
0:75* – + – –
0:100 – – + –
* 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.
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 50) 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 51). Otherwise, SSP is automatically
disabled.