Learn About Cache Settings and Performance

Related Topics

Cache memory is an area of temporary volatile storage (RAM) on the controller that has a faster access time than the drive media. By using cache memory, you can increase overall I/O performance because:

To measure cache effectiveness, examine the cache hit percentage in the Performance Monitor. This value shows the percentage of data requests that are serviced by the cache and did not require a disk access.

Storage Subsystem Cache Settings

Use the Storage Subsystem >> Change >> Cache Settings pull-down menu option to specify, for all logical drives in the storage subsystem, the:

When the cache holds the specified start percentage of unwritten data, a flush is triggered. When the cache flushes down to the specified stop percentage, the flush is stopped. For example, you can specify that the controller start flushing the cache when the cache reaches 80% full and stop flushing the cache when the cache reaches 16% full.

Note: Both the Start flushing and Stop flushing parameters in this version of the storage management software are percentages of the total cache memory. The Stop flushing parameter is NOT equal to the Demand Flush Amount parameter used in previous versions of this storage management software. (The Demand Flush Amount parameter was a specified percentage of the Demand Flush Threshold; neither of these parameters are currently used.)

Logical Drive Cache Settings

Use the Logical Drive >> Change >> Cache Settings pull-down menu option to enable or set read and write caching, write cache mirroring, write caching without batteries, and a cache read-ahead multiplier for a selected logical drive.

Related Topics

Changing Storage Subsystem Cache Settings

Changing Logical Drive Properties

Learn About Cache Memory Protection

Monitoring Performance