## Understanding creating arrays

When you group one or more hard disk drives together and configure the ServeRAID controller to access them in a particular pattern, you create a disk array. The ServeRAID controller currently supports up to eight independent arrays.

Disk arrays are used to improve security, performance, and reliability. The amount of improvement depends on the application programs that you run on the server, ServeRAID parameters, and the RAID levels that you assign to the logical drives in your arrays. The ServeRAID controller supports RAID levels 0, 1, 1 Enhanced, 5, and 5 Enhanced.

Note: Each ServeRAID controller supports up to eight logical drives. If any of the existing arrays contain a RAID level-5 Enhanced logical drive, you can have only seven logical drives on a controller.

For an example and explanation of a specific configuration, see the Express configuration example.

### See also

Hard disk drive capacity and unusable space