90 lines
5.6 KiB
HTML
90 lines
5.6 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="concept" />
|
|
<meta name="DC.Title" content="Manage performance in optical media libraries" />
|
|
<meta name="abstract" content="This topic describes performance considerations for users of optical media libraries." />
|
|
<meta name="description" content="This topic describes performance considerations for users of optical media libraries." />
|
|
<meta name="DC.Relation" scheme="URI" content="rzam4optical.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rzam4perfoptmedlib.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="http://www-1.ibm.com/servers/eserver/iseries/optical/performance/optperfc.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="../rzau8/considerations.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="../rzau8/bufferio.htm" />
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 2004, 2006" />
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2004, 2006" />
|
|
<meta name="DC.Format" content="XHTML" />
|
|
<meta name="DC.Identifier" content="rzam4mgeperfoptmedlib" />
|
|
<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>Manage performance in optical media libraries</title>
|
|
</head>
|
|
<body id="rzam4mgeperfoptmedlib"><a name="rzam4mgeperfoptmedlib"><!-- --></a>
|
|
<img src="./delta.gif" alt="Start of change" /><!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
|
<h1 class="topictitle1">Manage performance in optical media libraries</h1>
|
|
<div><p>This topic describes performance considerations for users of optical
|
|
media libraries.</p>
|
|
<p>Several factors can affect the optical performance of both LAN-attached
|
|
and directly-attached optical media libraries. This topic explains
|
|
how these factors can influence optical performance. </p>
|
|
<div class="section"><h4 class="sectiontitle">Volume mounting and dismounting</h4><p>Volume mounting
|
|
and dismounting are important factors that affect optical performance. It
|
|
takes approximately 8 to 15 seconds to remove a volume, store it in a slot,
|
|
retrieve a new volume, and mount it. If you can minimize the number of volume
|
|
mounts and dismounts that your application requires, optical performance will
|
|
improve.</p>
|
|
</div>
|
|
<div class="section"><h4 class="sectiontitle">Drive contention</h4><p>Performance can be severely affected
|
|
by drive contention. The following conditions increase drive contention and
|
|
should be avoided:</p>
|
|
<ul><li>Only one drive is available for use by applications libraries.</li>
|
|
<li>Many optical processes are running that attempt to use different optical
|
|
volumes at the same time.</li>
|
|
</ul>
|
|
</div>
|
|
<div class="section"><h4 class="sectiontitle">Number of directories and files</h4><p>Performance can
|
|
be affected by having too few directories with too many files. Directories
|
|
group related information to provide a means of quicker access. Typically,
|
|
you get better performance from more directories with fewer files. Although
|
|
there is no enforced limit on how many files there can be in a directory,
|
|
you probably should not have more than 6000 for performance reasons.</p>
|
|
</div>
|
|
<div class="section"><h4 class="sectiontitle">File size</h4><p>The size of a file has a direct effect
|
|
on the amount of time it takes to read, write, or copy the file. In general,
|
|
the larger the file, the longer the operation can be expected to take.</p>
|
|
</div>
|
|
<div class="section"><h4 class="sectiontitle">Add optical cartridge performance</h4><p> Specifying *NO
|
|
for the Rebuild Directory Index can improve the performance of <span class="cmdname">Add
|
|
Optical Cartridge (ADDOPTCTG)</span> by deferring the build of the optical
|
|
directory index until a later time. </p>
|
|
</div>
|
|
</div>
|
|
<div>
|
|
<ul class="ullinks">
|
|
<li class="ulchildlink"><strong><a href="rzam4perfoptmedlib.htm">Performance considerations for directly-attached optical media libraries</a></strong><br />
|
|
This topic discusses performance considerations that are specific to directly-attached optical libraries.</li>
|
|
</ul>
|
|
|
|
<div class="familylinks">
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzam4optical.htm" title="This topic provides an overview and reference guide for IBM optical support on the iSeries server with the i5/OS operating system.">Optical storage</a></div>
|
|
</div>
|
|
<div class="relconcepts"><strong>Related concepts</strong><br />
|
|
<div><a href="../rzau8/considerations.htm">Volume, directory, and file considerations</a></div>
|
|
<div><a href="../rzau8/bufferio.htm">Expanding buffer I/O through HFS</a></div>
|
|
</div>
|
|
<div class="relinfo"><strong>Related information</strong><br />
|
|
<div><a href="http://www-1.ibm.com/servers/eserver/iseries/optical/performance/optperfc.htm" target="_blank">Performance considerations</a></div>
|
|
</div>
|
|
</div>
|
|
<img src="./deltaend.gif" alt="End of change" /></body>
|
|
</html> |