source: trunk/server/docs-xml/manpages-3/idmap_autorid.8.xml

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<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
<refentry id="idmap_autorid.8">

<refmeta>
        <refentrytitle>idmap_autorid</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>idmap_autorid</refname>
        <refpurpose>Samba's idmap_autorid Backend for Winbind</refpurpose>
</refnamediv>

<refsynopsisdiv>
        <title>DESCRIPTION</title>
        <para>The idmap_autorid backend provides a way to use an algorithmic
        mapping scheme to map UIDs/GIDs and SIDs that is more deterministic
        than idmap_tdb and easier to configure than idmap_rid.</para>
        <para>The module works similar to idmap_rid, but it automatically
        configures the range to be used for each domain, so there is no need
        to specify a specific range for each domain in the forest, the only
        configuration that is needed is the range of uid/gids that shall
        be used for user/group mappings and an optional size of the ranges
        to be used.</para>
        <para>The mappings of which domain is mapped to which range is stored
        in autorid.tdb, thus you should backup this database regularly.</para>
        <para>Due to the algorithm being used, it is the module that is
        most easy to use as it only requires a minimal configuration.</para>
</refsynopsisdiv>

<refsect1>
        <title>IDMAP OPTIONS</title>

        <variablelist>
                <varlistentry>
                <term>rangesize = numberofidsperdomain</term>
                <listitem><para>
                        Defines the available number of uids/gids per domain. The
                        minimum needed value is 2000. SIDs with RIDs larger than this
                        value cannot be mapped, are ignored and the corresponding map
                        is discarded. Choose this value carefully, as this should
                        not be changed after the first ranges for domains have been
                        defined, otherwise mappings between domains will get intermixed
                        leading to unpredictable results. Please note that RIDs in Windows
                        Domains usually start with 500 for builtin users and 1000
                        for regular users. As the parameter cannot be changed later, please
                        plan accordingly for your expected number of users in a domain
                        with safety margins.
                        </para>
                        <para>One range will be used for local users and groups.
                        Thus the number of local users and groups that can be created is
                        limited by this option as well. If you plan to create a large amount
                        of local users or groups, you will need set this parameter accordingly.
                        </para>
                <para>The default value is 100000.</para>
                </listitem>
                </varlistentry>
        </variablelist>
</refsect1>

<refsect1>
        <title>THE MAPPING FORMULAS</title>
        <para>
                The Unix ID for a RID is calculated this way:
                <programlisting>
                        ID = IDMAP UID LOW VALUE + DOMAINRANGENUMBER * RANGESIZE + RID
                </programlisting>
        </para>
        <para>
                Correspondingly, the formula for calculating the RID for a
                given Unix ID is this:
                <programlisting>
                        RID = ID - IDMAP UID LOW VALUE - DOMAINRANGENUMBER * RANGESIZE
                </programlisting>
        </para>
</refsect1>

<refsect1>
        <title>EXAMPLES</title>
        <para>
                This example shows you the minimal configuration that will
                work for the principial domain and 19 trusted domains.
        </para>

        <programlisting>
        [global]
        security = ads
        workgroup = CUSTOMER
        realm = CUSTOMER.COM

        idmap config * : backend = autorid
        idmap config * : range = 1000000-1999999

        </programlisting>

        <para>
                This example shows how to configure idmap_autorid as default
                for all domains with a potentially large amount of users
                plus a specific configuration for a trusted domain
                that uses the SFU mapping scheme. Please note that idmap
                ranges and sfu ranges are not allowed to overlap.
        </para>

        <programlisting>
        [global]
        security = ads
        workgroup = CUSTOMER
        realm = CUSTOMER.COM

        idmap config * : backend = autorid
        idmap config * : range = 1000000-19999999
        idmap config * : rangesize = 1000000

        idmap config TRUSTED : backend  = ad
        idmap config TRUSTED : range    = 50000 - 99999
        idmap config TRUSTED : schema_mode = sfu
        </programlisting>

</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>