Introduction to RAID

Introduction to RAID

RAID is an array, or group, of multiple independent physical drives that provide high performance and fault tolerance. A RAID drive group improves I/O performance and reliability. The RAID drive group appears to the host computer as a single storage unit or as multiple virtual units. I/O is expedited because several drives can be accessed simultaneously.

RAID Benefits

RAID drive groups improve data storage reliability and fault tolerance compared to single-drive storage systems. Data loss resulting from a drive failure can be prevented by reconstructing missing data from the remaining drives. RAID improves I/O performance and increases storage subsystem reliability.

RAID Functions

Virtual drives are drive groups or spanned drive groups that are available to the operating system. The storage space in a virtual drive is spread across all of the drives in the drive group.

Your drives must be organized into virtual drives in a drive group, and they must be able to support the RAID level that you choose. Some common RAID functions follow:

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Creating hot spare drives.

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Configuring drive groups and virtual drives.

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Initializing one or more virtual drives.

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Accessing controllers, virtual drives, and drives individually.

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Rebuilding failed drives.

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Verifying that the redundancy data in virtual drives using RAID level 1, 5, 6, 10, 50, or 60 is correct.

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Reconstructing virtual drives after changing RAID levels or adding a drive to a drive group.

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Selecting a host controller on which to work.