source: vendor/3.6.25/docs-xml/manpages-3/vfs_fileid.8.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
<refentry id="vfs_fileid.8">

<refmeta>
        <refentrytitle>vfs_fileid</refentrytitle>
        <manvolnum>8</manvolnum>
        <refmiscinfo class="source">Samba</refmiscinfo>
        <refmiscinfo class="manual">System Administration tools</refmiscinfo>
        <refmiscinfo class="version">3.6</refmiscinfo>
</refmeta>


<refnamediv>
        <refname>vfs_fileid</refname>
        <refpurpose>Generates file_id structs with unique device id values for
        cluster setups</refpurpose>
</refnamediv>

<refsynopsisdiv>
        <cmdsynopsis>
                <command>vfs objects = fileid</command>
        </cmdsynopsis>
</refsynopsisdiv>

<refsect1>
        <title>DESCRIPTION</title>

        <para>This VFS module is part of the
        <citerefentry><refentrytitle>samba</refentrytitle>
        <manvolnum>7</manvolnum></citerefentry>
        suite.</para>

        <para>Samba uses file_id structs to uniquely identify files
        for locking purpose. By default the file_id contains the device
        and inode number returned by the <command>stat()</command> system call.
        As the file_id is a unique identifier of a file, it must be the same
        on all nodes in a cluster setup. This module overloads the
        <command>SMB_VFS_FILE_ID_CREATE()</command> operation and
        generates the device number based on the configured algorithm
        (see the "fileid:algorithm" option).
        </para>
</refsect1>


<refsect1>
        <title>OPTIONS</title>

        <variablelist>

                <varlistentry>
                <term>fileid:algorithm = ALGORITHM</term>
                <listitem>
                <para>Available algorithms are <command>fsname</command>
                and <command>fsid</command>. The default value is
                <command>fsname</command>.
                </para>
                <para>The <command>fsname</command> algorithm generates
                device id by hashing the kernel device name.
                </para>
                <para>The <command>fsid</command> algorithm generates
                the device id from the <command>f_fsid</command> returned
                from the <command>statfs()</command> syscall.
                </para>
                </listitem>
                </varlistentry>

                <varlistentry>
                <term>fileid:mapping = ALGORITHM</term>
                <listitem>
                <para>This option is the legacy version of the
                <command>fileid:algorithm</command> option, which was used in earlier
                versions of fileid mapping feature in custom Samba 3.0 versions.
                </para>
                </listitem>
                </varlistentry>

        </variablelist>
</refsect1>

<refsect1>
        <title>EXAMPLES</title>

        <para>Usage of the <command>fileid</command> module with the
        <command>fsid</command> algorithm:</para>

<programlisting>
        <smbconfsection name="[global]"/>
        <smbconfoption name="vfs objects">fileid</smbconfoption>
        <smbconfoption name="fileid:algorithm">fsid</smbconfoption>
</programlisting>

</refsect1>

<refsect1>
        <title>VERSION</title>

        <para>This man page is correct for version 3.2 of the Samba suite.
        </para>
</refsect1>

<refsect1>
        <title>AUTHOR</title>

        <para>The original Samba software and related utilities
        were created by Andrew Tridgell. Samba is now developed
        by the Samba Team as an Open Source project similar
        to the way the Linux kernel is developed.</para>

</refsect1>

</refentry>