52 lines
3.0 KiB
HTML
52 lines
3.0 KiB
HTML
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<?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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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="DC.Type" content="topic" />
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<meta name="DC.Title" content="Disk-unit level protection" />
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<meta name="DC.Relation" scheme="URI" content="rzalymirror3.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 2002, 2006" />
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<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2002, 2006" />
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<meta name="DC.Format" content="XHTML" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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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>Disk-unit level protection</title>
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</head>
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<body id="hdrlopdsk"><a name="hdrlopdsk"><!-- --></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">Disk-unit level protection</h1>
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<div><div class="fignone"><p>Mirrored protection always provides disk-unit level protection because
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the storage units are duplicated. If your main concern is protection of data
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and not high availability, then disk-unit level protection might be adequate.
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The disk unit is the most likely hardware component to fail, and disk-unit
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level protection keeps your system available after a disk unit failure.</p>
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<p><a href="rzalycmaintdef.htm">Concurrent maintenance</a> is
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often possible for certain types of disk unit failures that have disk-unit
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level protection.</p>
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<br /><img src="rzaix513.gif" alt="Figure showing the elements of disk unit-level protection" /><br /><p>This figure shows the elements of disk unit level protection: one bus,
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connected to one I/O processor, connected to one I/O adapter, which is attached
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to two separate disk units. The two storage units make a mirrored pair. With
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disk-unit level protection, the system continues to operate after a disk unit
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failure. If the I/O adapter or I/O processor fails, the system cannot access
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data on either of the storage units of the mirrored pair, and the system is
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unusable.</p>
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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="rzalymirror3.htm">Determine the level of protection that you want</a></div>
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</div>
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</div>
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</body>
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</html>
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