Creating Arrays Using Advanced Options

If advanced options are supported by your controller, click Advanced in the Create Array wizard to select the advanced options. Not all options are displayed for all controllers. The options displayed depends on the feature set that your controller supports.  Be sure to check your controller documentation to verify the controller features.

 
Advanced Options
Step 1

Spanned volumes—combine segments from two or more drives to form a volume.

RAID volumes—combine two or more arrays of the same type.

Write caching—store data in cache memory on the controller.

Battery enabled—protect data currently in cache in the event of a power failure

Read caching—pre-load data into the controller's cache memory

Step 2

Limit array capacity—choose the capacity of the array you are creating.

Stripe size—determine how much data is written on each drive for a given stripe across multiple drives in RAID 0, 5, 10, or 50.

Step 3

Initialization options:

Build—For a RAID 1, the data from the primary or master drive is copied to the secondary or slave drive. For a RAID 5, correct parity is generated for the entire array.

Clear—Clear contents of all selected drives.

Quick—The array is available immediately.

Initialization Priority—Adjusts the priority of the initialization task. The default is High and initialization completes as fast as possible.

Write Caching

When write caching is enabled, the controller stores the data in cache memory on the controller and accepts another write to this array as soon as the data from the previous write is safely stored in the controller’s memory.

Since writing data to memory is much faster than writing it to the drives, enabling write caching can significantly improve performance. All data stored in the cache is written to the drives when it is most efficient for the controller.

Read Caching

When enabled, the controller monitors read access to this array to try to predict where future reads may occur. If a pattern is detected, the data that seems most likely to be read next is pre-loaded 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. The default is Enabled.

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, at a minimum, you must use this option to limit the size of the first array.

For example, if you have two 18 GB drives, and you wish to use them to create two 9 GB RAID 1 arrays, 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 drive.

Stripe Size

The default stripe size has been chosen to maximize performance for most typical applications. Changing the stripe size may adversely affect performance.

For arrays which need to be initialized such as RAID 1 and RAID 5, advanced options may allow you to select which method is used to initialize and set the priority of the initialization task.