Promise Technology VTRAK E610f User Manual

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Chapter 7: Technology Background
This chapter covers the following topics:
• Introduction to RAID (below)
• “Choosing a RAID Level” on page 284
• “Choosing Stripe Size” on page 287
• “Choosing Sector Size” on page 287
• “Cache Policy” on page 288
• “Cache Mirroring” on page 290
• “LUN Affinity” on page 291
• “Capacity Coercion” on page 293
• “Initialization” on page 293
• “Hot Spare Drive(s)” on page 294
• “Partition and Format the Logical Drive” on page 294
• “RAID Level Migration” on page 294
• “Media Patrol” on page 301
• “Predictive Data Migration (PDM)” on page 302
• “Transition” on page 303
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:
• Higher data transfer rates for increased server performance
• Increased overall storage capacity for a single drive designation (such as, C,
D, E, etc.)
• 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 284. The following
outline breaks down the properties for each type of RAID logical drive:

Promise Technology VTRAK E610f Specifications

General

Brand	Promise Technology
Model	VTRAK E610f
Category	Storage
Language	English