81 lines
4.7 KiB
HTML
81 lines
4.7 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="Benefits of geographic mirroring" />
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<meta name="DC.Relation" scheme="URI" content="rzalygeographicmirror.htm" />
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<meta name="DC.Relation" scheme="URI" content="rzalymirrorconcept.htm" />
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<meta name="DC.Relation" scheme="URI" content="rzalydpp.htm" />
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<meta name="DC.Relation" scheme="URI" content="rzalypoolthreshold.htm" />
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<meta name="DC.Relation" scheme="URI" content="rzalyexamplegeomirror.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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<meta name="DC.Identifier" content="rzalygeobenefits" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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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>Benefits of geographic mirroring</title>
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</head>
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<body id="rzalygeobenefits"><a name="rzalygeobenefits"><!-- --></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">Benefits of geographic mirroring</h1>
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<div><p>Geographic mirroring provides these benefits:</p>
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<ul><li>Geographic mirroring provides site disaster protection by keeping a copy
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of the independent disk pool at another site which can be geographically distant.
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Having an additional copy at another geographic dispersed site improves availability. </li>
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<li>Geographic mirroring provides high availability with more
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backup nodes than switchable independent disk pools. In addition to having
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a production copy and mirrored copy, backup node possibilities are expanded
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when the independent disk pool is configured as switchable in an expansion
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unit (frame/unit), on an IOP on a shared bus, or on an IOP that is assigned
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to an I/O pool. </li>
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</ul>
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<div class="p">The geographically mirrored independent disk pool maintains all of the
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benefits of an independent disk pool, with its ability to be made available
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or unavailable as well as allow flexibility for the following actions:<ul><li>You can protect the production copy and
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mirror copy with your choice of protection, either disk unit mirroring or
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device parity protection. The production copy and mirror copy are not required
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to have the same type of protection.</li>
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<li>You can set the threshold of the disk pool to warn you when storage space
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is running low. The server sends a message, allowing you the time to add more
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storage space or to delete unnecessary objects. If the user ignores the warning
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and the mirror copy disk pool becomes full, geographic mirroring is suspended.
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If the user ignores the warning and the production disk pool becomes full,
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the application stops and objects cannot be created.</li>
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<li>The mirror copy can be detached and then separately made available to
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perform save operations, to create reports, or to perform data mining. When
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the mirror copy is reattached, it is synchronized with the production copy,
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and all modifications made to the detached copy are lost. Synchronization
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can be a lengthy process.</li>
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<li>If you configure the independent disk pools to be switchable, you increase
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your options to have more backup nodes that allow for failover and switchover
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methods.</li>
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</ul>
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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="rzalygeographicmirror.htm">Geographic mirroring</a></div>
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</div>
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<div class="relconcepts"><strong>Related concepts</strong><br />
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<div><a href="rzalydpp.htm">Device parity protection</a></div>
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<div><a href="rzalyexamplegeomirror.htm">Example: Independent disk pools with geographic mirroring</a></div>
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</div>
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<div class="relinfo"><strong>Related information</strong><br />
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<div><a href="rzalymirrorconcept.htm">Mirrored protection</a></div>
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<div><a href="rzalypoolthreshold.htm">Set the threshold of a disk pool</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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