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<h1>Understanding RAID technology</h1>
<p>Redundant array of independent disk (RAID) is the technology of grouping several
  <b>physical</b> drives in a computer into an pool that you can define
  as one or more logical devices. Each <b>logical device</b> appears to the operating
  system as a single drive. This grouping technique greatly enhances logical-drive
  capacity and performance beyond the physical limitations of a single physical
  drive.
<p>When you group multiple physical drives into a logical device, the controller
  can transfer data in parallel from the multiple drives in the pool.
  This parallel transfer yields data-transfer rates that are many times higher
  than with nonarrayed drives. This increased speed makes the system better able
  to meet the <b>throughput</b> (the amount of data processed in a given amount
  of time) or productivity needs of the multiple-user network environment.
<p>The ability to respond to multiple data requests provides not only an increase
  in throughput, but also a decrease in response time. The combination of parallel
  transfers and simultaneous responses to multiple requests enables disk arrays
  to provide a high level of performance in network environments.<b>&nbsp; </b>
<h2>More information</h2>
<ul>
  <li><a href="cchgraid.htm">Things to consider when changing the RAID level</a>
  <li> <a href="cstripe.htm">Understanding stripe size</a>
  <li><a href="craid0.htm">RAID level-0</a>
  <li><a href="craid1.htm">RAID level-1</a>
  <li><a href="craid1e.htm">RAID level-1 Enhanced</a>
  <li><a href="craid5.htm">RAID level-5</a>
  <li><a href="craid5ee.htm">RAID level-5E Enhanced</a>
  <li><a href="craid6.htm">RAID level-6</a>
  <li><a href="craidx0.htm">RAID level-x0</a>
  <li><a href="craidvol.htm">RAID volumes</a>
</ul>

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