Adaptec SCSI RAID 2120S/2200S Software User’s Guide

Enable Or Disable Read Caching—When enabled, the controller will monitor read accesses to this array to try to predict where future reads may occur. If it detects a pattern, the data that seems most likely to be read next will be preloaded into the controller’s cache memory. Since reading data from memory on the controller is much faster than reading it from the drives, this can have a significant impact on performance.

This setting defaults to Enabled.

Step 2 of 3 in the Advanced area of the Create Array wizard offers the following additional options:

Limit Array Capacity—This option allows you to choose the capacity of the array you are creating. The default is to make the array the largest possible size with the drives selected. To create multiple arrays on a single set of drives you must use this option to limit the size of, at a minimum, the first array.

For example, if you have two 18 GB drives, and you wish to use them to create two 9 GB RAID-1s, you would use this option to restrict the size of the first array you create.

Note: A RAID-1 uses two drives to create a mirror; that is all data written to a RAID-1 is written to both drives limiting the capacity of the array to the capacity of the smaller drives.

Stripe Size—For a RAID-0, 5, 10 or 50 where data is striped across multiple drives, stripe size determines how much data is written on each drive for a given stripe.

Note: The default stripe size has been chosen to maximize performance for most typical applications. Changing the stripe size is likely to adversely affect performance.

3-14