Thecus Y.E.S. Box N2100, Руководство пользователя

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Appendix B: RAID Basics
This appendix includes basic information about RAID and RAID settings.
RAID Introduction
A Redundant Array of Independent Disks (RAID) is an array of several hard disks
that provide data security and high performance. A RAID system accesses several
hard disks simultaneously, which improves I/O performance over a single hard disk.
Data security is enhanced by a RAID, since data loss due to a hard disk failure is
minimized by regenerating redundant data from the other RAID hard disks.
Benefits
RAID improves I/O performance, and increases data security through fault tolerance
and redundant data storage.
Improved Performance
RAID provides access to several hard disk drives simultaneously, which greatly
increases I/O performance.
Data Security
Hard disk drive failure unfortunately is a common occurrence. A RAID helps prevent
against the loss of data due to hard disk failure. A RAID offers additional hard disk
drives that can avert data loss from a hard disk drive failure. If a hard drive fails, the
RAID volume can regenerate data from the data and parity stored on its other hard
disk drives.
RAID Configuration
The N2100 YES Box supports both RAID 0 and RAID 1. A RAID system divides data
into smaller pieces (stripe) and saves these small pieces on two different hard disks
for better performance and protection against single hard disk failure. To setup RAID
on your system, you must configure stripe size and the type of RAID you wish to use.
Stripe Size
The system writes data in stripes across the multiple hard disks of a RAID. Since
multiple disks are accessed at the same time, disk striping enhances performance.
The stripes can vary in size and are interleaved sequentially.
Term Definition
Stripe Width The number of hard disk drives that are striped to. In a RAID
with four hard disks the stripe width is four.