58 lines
3.4 KiB
HTML
58 lines
3.4 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8"?>
|
||
|
|
<!DOCTYPE html
|
||
|
|
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
|
|
<html lang="en-us" xml:lang="en-us">
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||
|
|
<meta name="security" content="public" />
|
||
|
|
<meta name="Robots" content="index,follow" />
|
||
|
|
<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
|
||
|
|
<meta name="DC.Type" content="topic" />
|
||
|
|
<meta name="DC.Title" content="Input/output operations during a rebuild process" />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rzalydppprf.htm" />
|
||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 2002, 2006" />
|
||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2002, 2006" />
|
||
|
|
<meta name="DC.Format" content="XHTML" />
|
||
|
|
<meta name="DC.Identifier" content="hdropsrbldproc" />
|
||
|
|
<meta name="DC.Language" content="en-us" />
|
||
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
||
|
|
<!-- US Government Users Restricted Rights -->
|
||
|
|
<!-- Use, duplication or disclosure restricted by -->
|
||
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ic.css" />
|
||
|
|
<title>Input/output operations during a rebuild process</title>
|
||
|
|
</head>
|
||
|
|
<body id="hdropsrbldproc"><a name="hdropsrbldproc"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">Input/output operations during a rebuild process</h1>
|
||
|
|
<div><p>I/O operations during the rebuild (synchronization) process of the failed
|
||
|
|
disk unit may not require additional disk I/O requests. This depends on where
|
||
|
|
the data is read from or written to on the disk unit that is in the synchronization
|
||
|
|
process. For example: </p>
|
||
|
|
<ul><li>A read operation from the disk area that already has been rebuilt requires
|
||
|
|
one read operation.</li>
|
||
|
|
<li>A read operation from the disk area that has not been rebuilt is treated
|
||
|
|
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>
|
||
|
|
<li>A write operation to the disk area that has already been
|
||
|
|
rebuilt requires normal read and write operations (two read operations and
|
||
|
|
two write operations).</li>
|
||
|
|
<li>A write operation to the disk area that has not been rebuilt is treated
|
||
|
|
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>
|
||
|
|
</ul>
|
||
|
|
<div class="note"><span class="notetitle">Note:</span> <ol><li>The rebuild process takes longer when read and write operations to a replaced
|
||
|
|
disk unit are also occurring. Every read request or every write request interrupts
|
||
|
|
the rebuild process to perform the necessary I/O operations.</li>
|
||
|
|
<li> RAID 6 operations are derived from RAID 5, but at a further level of
|
||
|
|
complexity. Because the concept is similar to RAID 5, RAID 6 read operations
|
||
|
|
are not described here</li>
|
||
|
|
</ol>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzalydppprf.htm">How device parity protection affects performance</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|