RAID 10
Keywords: Nytro SW UG

> RAID 10

> RAID 10 is a combination of RAID 0 and RAID 1, and it consists of stripes across mirrored drives. RAID 10 breaks up data into smaller blocks, and then mirrors the blocks of data to each RAID 1 drive group. The first RAID 1 drive in each drive group then duplicates its data to the second drive. The size of each block is determined by the stripe size parameter, which is set during the creation of the RAID set. The RAID 1 virtual drives must have the same stripe size.

> Spanning is used because one virtual drive is defined across more than one drive group. Virtual drives defined across multiple RAID 1 level drive groups are referred to as RAID level 10, (RAID 1 + RAID 0). Data is striped across drive groups to increase performance by enabling access to multiple drive groups simultaneously.

> Each spanned RAID 10 virtual drive can tolerate multiple drive failures, as long as each failure is in a separate drive group. If drive failures occur, less than total drive capacity is available.

> Configure RAID 10 by spanning two contiguous RAID 1 virtual drives, up to the maximum number of supported devices for the controller. RAID 10 supports a maximum of eight spans, with a maximum of 8 drives per span. You must use an even number of drives in each RAID 10 virtual drive in the span.

> NOTE Other factors, such as the type of controller, can restrict the number of drives supported by RAID 10 virtual drives.

> The following table provides an overview of RAID 10.

> Table 4. RAID 10 Overview

> Uses | Appropriate when used with data storage that needs 100 percent redundancy of RAID 1 (mirrored drive groups) and that also needs the enhanced I/O performance of RAID 0 (striped drive groups.) RAID 10 works well for medium-sized databases or any environment that requires a higher degree of fault tolerance and moderate-to-medium capacity.
> Strong Points | Provides both high data transfer rates and complete data redundancy.
> Weak Points | Requires twice as many drives as all other RAID levels except RAID 1.
> Drives | 4 or 8.

> In the following figure, virtual drive 0 is created by distributing data across four drive groups (drive groups 0 through 3).

> Figure 5. RAID 10 Level Virtual Drive

DB15-001059-00-April 2013
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