| 1 | <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>vfs_cacheprime</title><link rel="stylesheet" href="../samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.74.0"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en"><a name="vfs_cacheprime.8"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>vfs_cacheprime — prime the kernel file data cache</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="literal">vfs objects = cacheprime</code></p></div></div><div class="refsect1" lang="en"><a name="id2522914"></a><h2>DESCRIPTION</h2><p>This VFS module is part of the
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| 2 | <a class="citerefentry" href="samba.7.html"><span class="citerefentry"><span class="refentrytitle">samba</span>(7)</span></a> suite.</p><p>The <code class="literal">vfs_cacheprime</code> VFS module reads chunks
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| 3 | of file data near the range requested by clients in order to
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| 4 | make sure the data is present in the kernel file data cache at
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| 5 | the time when it is actually requested by clients. </p><p>The size of the disk read operations performed
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| 6 | by <code class="literal">vfs_cacheprime</code> is determined by the
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| 7 | cacheprime:rsize option. All disk read operations are aligned
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| 8 | on boundaries that are a multiple of this size. Each range of
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| 9 | the file data is primed at most once during the time the client
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| 10 | has the file open. </p><p>This module is stackable.</p></div><div class="refsect1" lang="en"><a name="id2483334"></a><h2>OPTIONS</h2><div class="variablelist"><dl><dt><span class="term">cacheprime:rsize = BYTES</span></dt><dd><p>The number of bytes with which to prime
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| 11 | the kernel data cache.</p><p>The following suffixes may be applied to BYTES:</p><div class="itemizedlist"><ul type="disc"><li><p><code class="literal">K</code> - BYTES is a number of kilobytes</p></li><li><p><code class="literal">M</code> - BYTES is a number of megabytes</p></li><li><p><code class="literal">G</code> - BYTES is a number of gigabytes</p></li></ul></div></dd></dl></div></div><div class="refsect1" lang="en"><a name="id2483392"></a><h2>EXAMPLES</h2><p>For a hypothetical disk array, it is necessary to ensure
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| 12 | that all read operations are of size 1 megabyte (1048576 bytes),
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| 13 | and aligned on 1 megabyte boundaries:
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| 14 | </p><pre class="programlisting">
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| 15 | <em class="parameter"><code>[hypothetical]</code></em>
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| 16 | <a class="link" href="smb.conf.5.html#VFSOBJECTS" target="_top">vfs objects = cacheprime</a>
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| 17 | <a class="link" href="smb.conf.5.html#CACHEPRIME:RSIZE" target="_top">cacheprime:rsize = 1M</a>
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| 18 | </pre></div><div class="refsect1" lang="en"><a name="id2483662"></a><h2>CAVEATS</h2><p><code class="literal">cacheprime</code> is not a a substitute for
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| 19 | a general-purpose readahead mechanism. It is intended for use
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| 20 | only in very specific environments where disk operations must
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| 21 | be aligned and sized to known values (as much as that is possible).
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| 22 | </p></div><div class="refsect1" lang="en"><a name="id2483680"></a><h2>VERSION</h2><p>This man page is correct for version 3.0.25 of the Samba suite.
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| 23 | </p></div><div class="refsect1" lang="en"><a name="id2483691"></a><h2>AUTHOR</h2><p>The original Samba software and related utilities
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| 24 | were created by Andrew Tridgell. Samba is now developed
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| 25 | by the Samba Team as an Open Source project similar
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| 26 | to the way the Linux kernel is developed.</p></div></div></body></html>
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