Summary of RAID Levels
Keywords: Nytro SW UG

> Summary of RAID Levels

> RAID 0 uses striping to provide high data throughput, especially for large files in an environment that does not require fault tolerance.

> RAID 1 uses mirroring so that data written to one drive is simultaneously written to another drive. RAID 1 is good for small databases or other applications that require small capacity but complete data redundancy.

> RAID 5 uses disk striping and parity data across all drives (distributed parity) to provide high data throughput, especially for small random access.

> RAID 10, a combination of RAID 0 and RAID 1, contains striped data across mirrored spans. A RAID 10 drive group is a spanned drive group that creates a striped set from a series of mirrored drives. RAID 10 allows a maximum of 8 spans. You must use an even number of drives in each RAID virtual drive in the span. The RAID 1 virtual drives must have the same stripe size. RAID 10 provides high data throughput and complete data redundancy but uses a larger number of spans.

> NOTE Having virtual drives of different RAID levels, such as RAID 0 and RAID 5, in the same drive group is not allowed. For example, if an existing RAID 5 virtual drive is created out of partial space in an array, the next virtual drive in the array has to be RAID 5 only.

> NOTE The MegaSR controller supports the standard RAID levels: RAID 0, RAID 1,and RAID 5. The MegaSR controller comes in two variants, SCU and AHCI, both supporting a maximum of eight physical drives. A maximum of eight virtual drives can be created (using RAID 0, RAID 1, and RAID 5 only) and controlled by the MegaSR controller. One virtual drive can be created on an array (a maximum of eight if no other virtual drives are already created on the MegaSR controller), or you can create eight arrays with one virtual drive each.

DB15-001059-00-April 2013
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