docs-xml/manpages/vfs_commit.8.xml

   1 <?xml version="1.0" encoding="iso-8859-1"?>
   2 <!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
   3 <refentry id="vfs_commit.8">
   4
   5 <refmeta>
   6         <refentrytitle>vfs_commit</refentrytitle>
   7         <manvolnum>8</manvolnum>
   8         <refmiscinfo class="source">Samba</refmiscinfo>
   9         <refmiscinfo class="manual">System Administration tools</refmiscinfo>
  10         <refmiscinfo class="version">4.2</refmiscinfo>
  11 </refmeta>
  12
  13
  14 <refnamediv>
  15         <refname>vfs_commit</refname>
  16         <refpurpose>flush dirty data at specified intervals</refpurpose>
  17 </refnamediv>
  18
  19 <refsynopsisdiv>
  20         <cmdsynopsis>
  21                 <command>vfs objects = commit</command>
  22         </cmdsynopsis>
  23 </refsynopsisdiv>
  24
  25 <refsect1>
  26         <title>DESCRIPTION</title>
  27
  28         <para>This VFS module is part of the
  29         <citerefentry><refentrytitle>samba</refentrytitle>
  30         <manvolnum>7</manvolnum></citerefentry> suite.</para>
  31
  32         <para>The <command>vfs_commit</command> VFS module keeps track of
  33         the amount of data written to a file and synchronizes it to
  34         disk when a specified amount accumulates.
  35         </para>
  36
  37         <para><command>vfs_commit</command> is useful in two
  38         circumstances. First, if you have very precious data, the
  39         impact of unexpected power loss can be minimized by a small
  40         commit:dthresh value. Secondly, write performance can be
  41         improved on some systems by flushing file data early and at
  42         regular intervals.</para>
  43
  44         <para>This module is stackable.</para>
  45
  46 </refsect1>
  47
  48
  49 <refsect1>
  50         <title>OPTIONS</title>
  51
  52         <variablelist>
  53
  54                 <varlistentry>
  55                 <term>commit:dthresh = BYTES</term>
  56                 <listitem>
  57                 <para>Synchronize file data each time the specified
  58                 number of bytes has been written.
  59                 </para>
  60
  61                 <para>The following suffixes may be applied to BYTES:</para>
  62                 <itemizedlist>
  63                 <listitem><para><command>K</command> - BYTES is a number of kilobytes</para></listitem>
  64                 <listitem><para><command>M</command> - BYTES is a number of megabytes</para></listitem>
  65                 <listitem><para><command>G</command> - BYTES is a number of gigabytes</para></listitem>
  66                 </itemizedlist>
  67
  68                 </listitem>
  69                 </varlistentry>
  70
  71         </variablelist>
  72 </refsect1>
  73
  74 <refsect1>
  75         <title>EXAMPLES</title>
  76
  77         <para>Synchronize the file data on the [precious] share after
  78         every 512 kilobytes (524288 bytes) of data is written:</para>
  79 <programlisting>
  80         <smbconfsection name="[precious]"/>
  81         <smbconfoption name="path">/data/precious</smbconfoption>
  82         <smbconfoption name="vfs objects">commit</smbconfoption>
  83         <smbconfoption name="commit:dthresh">512K</smbconfoption>
  84 </programlisting>
  85 </refsect1>
  86
  87 <refsect1>
  88         <title>CAVEATS</title>
  89         <para>On some systems, the data synchronization performed by
  90         <command>commit</command> may reduce performance.
  91         </para>
  92 </refsect1>
  93
  94 <refsect1>
  95         <title>VERSION</title>
  96         <para>This man page is correct for version 3.0.25 of the Samba suite.
  97         </para>
  98 </refsect1>
  99
 100 <refsect1>
 101         <title>AUTHOR</title>
 102
 103         <para>The original Samba software and related utilities
 104         were created by Andrew Tridgell. Samba is now developed
 105         by the Samba Team as an Open Source project similar
 106         to the way the Linux kernel is developed.</para>
 107
 108 </refsect1>
 109
 110 </refentry>