Understanding Disk Array Technology

Understanding Disk Array Technology

When you connect several hard disks together and configure the RAID controller to access them in a predetermined pattern, you create a disk array. The ServeRAID controller on the system board 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 and the RAID levels that you assign to the logical drives in the arrays. The ServeRAID controller supports RAID levels 0, 1, and 5.

The server has space for up to six hot-swap hard disk drives.

Hard Disk Drive Capacities: Hard disk drive capacities influence the way you create arrays. Drives in the array can be of different capacities (1 GB 1 or 2GB, for example), but the ServeRAID controller treats them as if they all have the capacity of the smallest disk drive.

For example, if you group three 1GB drives and one 2GB drive into an array, the total capacity of the array is 1GB times 4, or 4GB, not the 5GB physically available.

Conversely, if you add a smaller drive to an array of larger drives, such as a 1GB drive to a group containing three 2GB drives, the total capacity of that array is 4GB, not the 7GB physically available. Therefore, the optimal way to create arrays is to use hard disk drives that have the same capacity.

Logical Drives: When you create an array, you group hard disk drives into one storage area. You can define this storage area as a single logical drive, or you can subdivide it into several logical drives. Each logical drive appears to the operating system as a single physical hard disk drive.

The ServeRAID controller on the system board supports up to eight logical drives. If you have only one array, you can define it as a single logical drive, or you can divide it into several logical drives. The first logical drive that you define will be the startup (boot) drive. If you have two or more arrays, each array can be one logical drive, or you can divide each array into multiple logical drives, as long as the total number of logical drives for all of the arrays does not exceed eight.

Back to  Jump to TOP-of-PAGE

Please see the LEGAL  -  Trademark notice.
Feel free - send a Email-NOTE  for any BUG on this page found - Thank you.