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Readcache, writecache, Rebuildpriority, expandpriority, Sspstate – HP Linux Server Management Software User Manual

Page 42

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Toolkit utilities 42

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

45

) 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.

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

45

) instead.

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