# Understanding RAID level-0

RAID level-0 stripes the data across all the drives in the array. This offers substantial speed enhancement, but provides no data redundancy. RAID level-0 provides the largest storage capacity of the RAID levels that are offered, because no room is taken for redundant data or data-parity storage.

RAID level-0 requires a minimum of one drive and, depending upon the level of firmware and the stripe-unit size, supports a maximum of 8 or 16 drives.

For ServeRAID-8i, ServeRAID-7t, and HostRAID controllers, RAID level-0 requires a minimum of two drives.

The following illustration shows an example of a RAID level-0 logical drive.

## RAID level-0 example

Start with two physical drives. |
Create an array using the two physical drives. |
Then create a logical drive within that array. |
The data is striped across the drives, creating blocks. Notice that the data is striped across all the drives in the array, but no redundant data is stored. |

A physical drive failure within the array results in loss of data in the logical drive assigned RAID level-0, but only in that logical drive. If you have logical drives assigned RAID level-1, 1E, 5, or 5E in the same array, they will not lose data.

Note: If you have an array that contains only one physical drive, you can assign only RAID level-0 to the logical drive in that array.

When you replace a failed drive, the controller can rebuild all the RAID level-1, 1E, 5, 5E, and 5EE logical drives automatically onto the replacement physical drive. However, any data stored in a failed RAID level-0 logical drive is lost.

Although the risk of data loss is present, you might want to assign RAID level-0 to one of the logical drives to take advantage of the speed this RAID level offers. You can use this logical drive to store data that you back up each day and can re-create easily. You also might want to use a RAID level-0 logical drive when you require maximum capacity.

RAID level-0 offers the following advantages and disadvantages.

Advantages | Disadvantages
--- | ---
Substantial speed enhancement Maximum utilization of physical drive storage capacity, because no room is taken for redundant data or data-parity storage | No data redundancy, resulting in data loss in the event that a physical drive fails

## More information

- Understanding RAID technology
- Understanding stripe-unit size
- Selecting a RAID level
- RAID level-1
- RAID level-1 Enhanced
- RAID level-5
- RAID level-5 Enhanced
- RAID level-5EE
- RAID level-6
- RAID level-x0
- RAID volumes
- Software and hardware support of RAID levels

Glossary | Contents

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