docs-xml/manpages/vfs_glusterfs.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_glusterfs.8">
   4
   5 <refmeta>
   6         <refentrytitle>vfs_glusterfs</refentrytitle>
   7         <manvolnum>8</manvolnum>
   8         <refmiscinfo class="source">Samba</refmiscinfo>
   9         <refmiscinfo class="manual">System Administration tools</refmiscinfo>
  10         <refmiscinfo class="version">&doc.version;</refmiscinfo>
  11 </refmeta>
  12
  13
  14 <refnamediv>
  15         <refname>vfs_glusterfs</refname>
  16         <refpurpose>
  17                 Utilize features provided by GlusterFS
  18         </refpurpose>
  19 </refnamediv>
  20
  21 <refsynopsisdiv>
  22         <cmdsynopsis>
  23                 <command>vfs objects = glusterfs</command>
  24         </cmdsynopsis>
  25 </refsynopsisdiv>
  26
  27 <refsect1>
  28         <title>DESCRIPTION</title>
  29
  30         <para>This VFS module is part of the
  31         <citerefentry><refentrytitle>samba</refentrytitle>
  32         <manvolnum>8</manvolnum></citerefentry> suite.</para>
  33
  34         <para>
  35                 GlusterFS
  36                 (<ulink url="http://www.gluster.org/">http://www.gluster.org</ulink>)
  37                 is an Open Source clustered file system capable of scaling to
  38                 several peta-bytes.  With its FUSE based native client,
  39                 GlusterFS is available as a POSIX compliant file system and can
  40                 hence be shared by Samba without additional steps.
  41         </para>
  42
  43         <para>
  44                 The <command>vfs_glusterfs</command> VFS module provides an
  45                 alternative, and superior way to access a Gluster filesystem
  46                 from Samba for sharing. It does not require a Gluster FUSE mount
  47                 but directly accesses the GlusterFS daemon through its library
  48                 <command>libgfapi</command>, thereby omitting the expensive
  49                 kernel-userspace context switches and taking advantage of some
  50                 of the more advanced features of GlusterFS.
  51         </para>
  52
  53         <para>
  54                 This module can be combined with other modules, but it
  55                 should be the last module in the <command>vfs objects</command>
  56                 list. Modules added to this list to the right of the glusterfs
  57                 entry may not have any effect at all.
  58         </para>
  59 </refsect1>
  60
  61 <refsect1>
  62         <title>CONFIGURATION</title>
  63
  64         <para>
  65                 A basic configuration looks like this.
  66         </para>
  67
  68         <programlisting>
  69                 <smbconfsection name="[share]"/>
  70                 <smbconfoption name="vfs objects">glusterfs</smbconfoption>
  71                 <smbconfoption name="path">/relative/base/path</smbconfoption>
  72                 <smbconfoption name="glusterfs:volume">gv0</smbconfoption>
  73                 <smbconfoption name="kernel share modes">no</smbconfoption>
  74         </programlisting>
  75
  76         <para>
  77                 Note that since <command>vfs_glusterfs</command> does not
  78                 require a Gluster mount, the share <command>path</command> is
  79                 treated differently than for other shares: It is interpreted as
  80                 the base path of the share relative to the gluster volume used.
  81                 Because this is usually not at the same time a system path, in a
  82                 ctdb cluster setup where ctdb manages Samba, you need to set
  83                 <command>CTDB_SAMBA_SKIP_SHARE_CHECK=yes</command> in ctdb's
  84                 configuration file. Otherwise ctdb will not get healthy.
  85         </para>
  86
  87         <para>
  88                 Note that currently kernel share modes have to be disabled
  89                 in a share running with the glusterfs vfs module for file
  90                 serving to work properly.
  91         </para>
  92 </refsect1>
  93
  94 <refsect1>
  95         <title>OPTIONS</title>
  96
  97         <variablelist>
  98
  99                 <varlistentry>
 100                 <term>glusterfs:logfile = path</term>
 101                 <listitem>
 102                 <para>
 103                         Defines whether and where to store a vfs_glusterfs specific
 104                         logfile. Client variable substitution is supported (i.e.
 105                         %M, %m, %I), hence per client log file can be specified.
 106                 </para>
 107                 <para>
 108                         Example: glusterfs:logfile =
 109                         /var/log/samba/glusterfs-vol2.%M.log
 110                 </para>
 111                 </listitem>
 112                 </varlistentry>
 113
 114                 <varlistentry>
 115                 <term>glusterfs:loglevel = 0-9</term>
 116                 <listitem>
 117                 <para>
 118                         Defines the level of logging, with higher numbers corresponding to more verbosity.
 119                         0 - No logs; 9 - Trace log level; 7 being the info log level is preferred.
 120                 </para>
 121                 <para>
 122                         If this option is not defined with an explicit loglevel,
 123                         the glusterfs default is used (currently loglevel 7).
 124                 </para>
 125                 </listitem>
 126                 </varlistentry>
 127
 128
 129                 <varlistentry>
 130                 <term>glusterfs:volfile_server = servername</term>
 131                 <listitem>
 132                 <para>
 133                         Defines which volfile server to use, defaults to
 134                         localhost. It could be list of white space
 135                         separated elements where each element could be
 136                 </para>
 137                 <para>
 138                         1. unix+/path/to/socket/file
 139                 </para>
 140                 <para>
 141                         2. [tcp+]IP|hostname|\[IPv6\][:port]
 142                 </para>
 143                 <para>
 144                         Note the restriction on naming a IPv6 host, it follows
 145                         the same restriction that is based on IPv6 naming in
 146                         URL as per RFC 2732.
 147                 </para>
 148                 </listitem>
 149                 </varlistentry>
 150
 151                 <varlistentry>
 152                 <term>glusterfs:volume = volumename</term>
 153                 <listitem>
 154                 <para>
 155                         Defines the glusterfs volumename to use for this share.
 156                 </para>
 157                 </listitem>
 158
 159                 </varlistentry>
 160         </variablelist>
 161
 162 </refsect1>
 163
 164 <refsect1>
 165         <title>CAVEATS</title>
 166
 167         <para>
 168                 The GlusterFS write-behind performance translator, when used
 169                 with Samba, could be a source of data corruption. The
 170                 translator, while processing a write call, immediately returns
 171                 success but continues writing the data to the server in the
 172                 background. This can cause data corruption when two clients
 173                 relying on Samba to provide data consistency are operating on
 174                 the same file.
 175         </para>
 176         <para>
 177                 The write-behind translator is enabled by default on GlusterFS.
 178                 The vfs_glusterfs plugin will check for the presence of the
 179                 translator and refuse to connect if detected.
 180                 Please disable the write-behind translator for the GlusterFS
 181                 volume to allow the plugin to connect to the volume.
 182                 The write-behind translator can easily be disabled via calling
 183                 <programlisting>
 184                         gluster volume set &lt;volumename&gt; performance.write-behind off
 185                 </programlisting> on the commandline.
 186         </para>
 187         <para>
 188                 With GlusterFS versions >= 9, we silently bypass write-behind
 189                 translator during initial connect and failure is avoided.
 190         </para>
 191
 192 </refsect1>
 193
 194
 195 <refsect1>
 196         <title>VERSION</title>
 197
 198         <para>
 199                 This man page is part of version &doc.version; of the Samba suite.
 200         </para>
 201 </refsect1>
 202
 203 <refsect1>
 204         <title>AUTHOR</title>
 205
 206         <para>The original Samba software and related utilities
 207         were created by Andrew Tridgell. Samba is now developed
 208         by the Samba Team as an Open Source project similar
 209         to the way the Linux kernel is developed.</para>
 210
 211 </refsect1>
 212
 213 </refentry>