68 lines
4.0 KiB
HTML
68 lines
4.0 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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<meta name="DC.Title" content="Contrast basic and independent disk pools" />
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<title>Contrast basic and independent disk pools</title>
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<body id="hdrcontrasting"><a name="hdrcontrasting"><!-- --></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">Contrast basic and independent disk pools</h1>
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<div><p>Basic disk pools and independent disk pools, also called auxiliary storage
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pools (ASPs) in the character-based interface, are both useful to group disk
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units containing certain information together; however, they have some inherent
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differences:</p>
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<ul><li>When the server performs an IPL, all of the disk units configured to a
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basic disk pool must be accounted for in order for the server to continue
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the IPL. Independent disk pools are not included in the IPL. When you vary
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on the independent disk pool, the node then verifies that all disk units are
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present.</li>
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<li>When an unprotected disk unit in a disk pool fails, it typically stops
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all normal processing on the server until it can be repaired. The total loss
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of a disk unit in a basic disk pool requires lengthy recovery procedures to
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restore the lost data before the server can IPL and resume normal operations.</li>
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<li>The data in a basic disk pool belongs to the attaching node and can only
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be directly accessed by that system. In an independent disk pool the data
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does not belong to the node, but it belongs to the independent disk pool.
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You can share the data in the independent disk pool between nodes in a cluster
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by varying it off of one node and varying it on to another node.</li>
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<li>When you create a basic disk pool, you assign the disk pool a number.
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When you create an independent disk pool, you name the disk pool and the system
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assigns a number.</li>
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<li>If a basic disk pool fills up, it can overflow excess data into the system
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disk pool. When this occurs, the disk pool loses the isolation and protection
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inherent in disk pools. Independent disk pools cannot overflow. If they did,
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they lose their independence. When the independent disk pool nears its threshold,
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you need to add more disk units or delete objects to create more storage space.</li>
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<li>When you make restricted changes to disk configuration in a basic disk
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pool you must have your server restarted to Dedicated Service Tools (DST).
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In an offline independent disk pool you do not need to have your server in
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DST mode to start or stop mirroring, start device parity protection, start
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compression, remove a disk unit, and so on.</li>
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</ul>
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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="rzalyuserasp.htm">Basic disk pools</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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