58 lines
3.4 KiB
HTML
58 lines
3.4 KiB
HTML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<meta name="DC.Type" content="topic" />
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<meta name="DC.Title" content="Input/output operations during a rebuild process" />
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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>Input/output operations during a rebuild process</title>
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</head>
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<body id="hdropsrbldproc"><a name="hdropsrbldproc"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Input/output operations during a rebuild process</h1>
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<div><p>I/O operations during the rebuild (synchronization) process of the failed
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disk unit may not require additional disk I/O requests. This depends on where
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the data is read from or written to on the disk unit that is in the synchronization
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process. For example: </p>
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<ul><li>A read operation from the disk area that already has been rebuilt requires
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one read operation.</li>
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<li>A read operation from the disk area that has not been rebuilt is treated
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as a read operation on a failed disk unit. See <a href="rzalyrdopsfail.htm">Read operations on a failed disk unit</a> for more information.</li>
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<li>A write operation to the disk area that has already been
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rebuilt requires normal read and write operations (two read operations and
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two write operations).</li>
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<li>A write operation to the disk area that has not been rebuilt is treated
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as a write operation to a failed disk unit. See <a href="rzalywrtopsfail.htm">Write operations on a failed disk unit</a> for more information.</li>
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</ul>
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<div class="note"><span class="notetitle">Note:</span> <ol><li>The rebuild process takes longer when read and write operations to a replaced
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disk unit are also occurring. Every read request or every write request interrupts
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the rebuild process to perform the necessary I/O operations.</li>
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<li> RAID 6 operations are derived from RAID 5, but at a further level of
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complexity. Because the concept is similar to RAID 5, RAID 6 read operations
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are not described here</li>
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</ol>
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</div>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzalydppprf.htm">How device parity protection affects performance</a></div>
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</div>
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</div>
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</body>
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