ATTO Technology S-Class manual Configuring Drives, Jbod Just a Bunch of Disks, RAID Level

6.0 Configuring Drives

The Diamond Storage Array can be configured as a JBOD, RAID Level 0, RAID Level 1, RAID Level 10 or RAID Level 5 array. Its default is JBOD. RAID is a storage configuration which uses multiple disk drives to increase capacity, performance and/or reliability.

You may configure your Diamond Storage Array in several different ways depending on your needs although the Diamond makes some choices for your. The following elements must be considered when you are configuring your Diamond.

•RAID level

•Interleave

•Hot Spares option

Using the ExpressNAV browser-based interface is the easiest way to set up your Diamond. You may also use the Command Line Interface commands.

CAUTION

Changing these parameters causes all previous drive data on the Diamond Storage Array to be erased. Make sure you back up all information before setting up a different configuration.

JBOD (Just a Bunch of Disks)

JBOD (Just a Bunch of Disks) configuration, the default for the Diamond Storage Array, allows many individual disk drives to be available for normal storage operations. A JBOD configuration allows you to access each disk drive in the array independently. Any action you can do to a normal disk drive can be performed on any disk in the JBOD.

RAID Level 0

RAID Level 0 (striping) is based on the fact that increased disk performance can be achieved by simultaneously accessing data across multiple disk drives in an array. This arrangement increases data transfer rates while reducing average access time by overlapping drive seeks. RAID Level 0 groups provide data that is striped across several drives. RAID Level 0 is pure striping, without redundancy, meaning there is no

data protection. If one disk fails, all data within that stripe set is lost.

RAID Level 0 is used by applications requiring high performance for non-critical data.

The QuickRAID0 command, accessed through the CLI, allows a simple, fast, out-of-the-box setup of the array into evenly-sized RAID Level 0 stripe groups.

RAID Level 1

RAID Level 1 (mirroring) ensures the security of data by writing the exact same data simultaneously to two or more different drives. This application is for users with critical data which cannot be lost or corrupted due to the failure of a single drive.

With RAID Level 1, the host will see what it believes to be a single physical disk of a specific size: it does not know or care about the mirrored pair. The RAID controller manages where data is written and read, allowing one disk to fail without the host knowing it has failed. The array will send notification of the failure over the serial or Ethernet port and the fault LED will be illuminated. Service personnel can then replace the failed drive and initiate a rebuild.

RAID Level 1 is used in applications containing mission critical data. The QuickRAID1 command, accessed through the Command Line Interface, allows a simple, fast, out-of-the-box setup of the array into RAID Level 1 mirrored groups.

RAID Level 10

RAID Level 10 (mirroring with striping) increases data transfer rates while ensuring security by writing the exact same data simultaneously to two or more different drives.

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ATTO Technology Inc. Diamond Storage Array Installation and Operation Manual