Chapter 7: technology background, Introduction to raid – Promise Technology Network Device EX8654 User Manual
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Chapter 7: Technology Background
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Introduction to RAID (below)
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Choosing a RAID Level (page 232)
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Choosing Stripe Block Size (page 236)
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Choosing Sector Size (page 236)
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Choosing Cache Policy (page 237)
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Partition and Format the Logical Drive (page 240)
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RAID Level Migration (page 240)
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Predictive Data Migration (PDM) (page 248)
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Critical & Offline Logical Drives (page 253)
Introduction to RAID
RAID (Redundant Array of Independent Disks) allows multiple physical drives to
be combined together in a disk array. Then all or a portion of the disk array is
formed into a logical drive. The operating system sees the logical drive as a
single storage device, and treats it as such.
The RAID software and controller manage all of the individual drives. The
benefits of a RAID can include:
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Higher data transfer rates for increased server performance
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Increased overall storage capacity for a single drive designation (such as, C,
D, E, etc.)
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Data redundancy/fault tolerance for ensuring continuous system operation in
the event of a hard drive failure
Different types of logical drives use different organizational models and have
varying benefits. Also see “Choosing a RAID Level” on page 232. The following
outline breaks down the properties for each type of RAID logical drive: