Compaq 3200 manual Accelerator Ratio, Expand an Array, Add or Configure Spare Drives, 5-33

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Accelerator Ratio

The Smart Array 3200 Controller has an onboard cache, called an Array Accelerator, that performs both write-posting and read-ahead caching. The setting in CPQONLIN determines the amount of memory allocated to the read and write caches. For example, if the Accelerator Ratio is set to Read 75% - Write 25%, then 75% of Array Accelerator cache is dedicated to read-ahead cache and 25% is dedicated to the write-posting cache. This option can be modified from the Controller Settings menu when the Array Accelerator is installed.

Expand an Array

During an expand, performance may be slightly degraded. In most cases, however, any potential degradation is offset by the addition of physical drives. Some tips for expanding are:

■Perform the expand process during periods of low server use. If you must expand during peak periods, the Array Configuration Utility for NetWare allows you to set the priority of the expand. Setting the priority to LOW will affect performance the least, but it will take longer for the new space to become available.

■When expanding, you must add drives of at least the same capacity as the smallest drive in the array. Adding larger drives wastes space because only the space that is equal to the smallest drive size can be used.

Add or Configure Spare Drives

When adding a spare drive to an array, you must have an unassigned drive or a drive already assigned as a spare on another array. You can assign a single spare to as many arrays as you want, or assign separate spares. When you select Assign Spare Drive, only drives that qualify will appear (for example, only those spares that are large enough will appear). If drives that you expect to see do not appear, switch to the physical drive view (TAB key), and check the size of the drives. The spare must be as large as the smallest drive in the array.

Compaq Smart Array 3200 Controller Reference Guide