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="idmap_autorid.8">
6 <refentrytitle>idmap_autorid</refentrytitle>
7 <manvolnum>8</manvolnum>
8 <refmiscinfo class="source">Samba</refmiscinfo>
9 <refmiscinfo class="manual">System Administration tools</refmiscinfo>
10 <refmiscinfo class="version">3.6</refmiscinfo>
15 <refname>idmap_autorid</refname>
16 <refpurpose>Samba's idmap_autorid Backend for Winbind</refpurpose>
20 <title>DESCRIPTION</title>
21 <para>The idmap_autorid backend provides a way to use an algorithmic
22 mapping scheme to map UIDs/GIDs and SIDs that is more deterministic
23 than idmap_tdb and easier to configure than idmap_rid.</para>
24 <para>The module works similar to idmap_rid, but it automatically
25 configures the range to be used for each domain, so there is no need
26 to specify a specific range for each domain in the forest, the only
27 configuration that is needed is the range of uid/gids that shall
28 be used for user/group mappings and an optional size of the ranges
30 <para>The mappings of which domain is mapped to which range is stored
31 in autorid.tdb, thus you should backup this database regularly.</para>
32 <para>Due to the algorithm being used, it is the module that is
33 most easy to use as it only requires a minimal configuration.</para>
37 <title>IDMAP OPTIONS</title>
41 <term>rangesize = numberofidsperdomain</term>
43 Defines the available number of uids/gids per domain. The
44 minimum needed value is 2000. SIDs with RIDs larger than this
45 value cannot be mapped, are ignored and the corresponding map
46 is discarded. Choose this value carefully, as this should
47 not be changed after the first ranges for domains have been
48 defined, otherwise mappings between domains will get intermixed
49 leading to unpredictable results. Please note that RIDs in Windows
50 Domains usually start with 500 for builtin users and 1000
51 for regular users. As the parameter cannot be changed later, please
52 plan accordingly for your expected number of users in a domain
55 <para>One range will be used for local users and groups.
56 Thus the number of local users and groups that can be created is
57 limited by this option as well. If you plan to create a large amount
58 of local users or groups, you will need set this parameter accordingly.
60 <para>The default value is 100000.</para>
67 <title>THE MAPPING FORMULAS</title>
69 The Unix ID for a RID is calculated this way:
71 ID = IDMAP UID LOW VALUE + DOMAINRANGENUMBER * RANGESIZE + RID
75 Correspondingly, the formula for calculating the RID for a
76 given Unix ID is this:
78 RID = ID - IDMAP UID LOW VALUE - DOMAINRANGENUMBER * RANGESIZE
84 <title>EXAMPLES</title>
86 This example shows you the minimal configuration that will
87 work for the principial domain and 19 trusted domains.
96 idmap config * : backend = autorid
97 idmap config * : range = 1000000-1999999
102 This example shows how to configure idmap_autorid as default
103 for all domains with a potentially large amount of users
104 plus a specific configuration for a trusted domain
105 that uses the SFU mapping scheme. Please note that idmap
106 ranges and sfu ranges are not allowed to overlap.
115 idmap config * : backend = autorid
116 idmap config * : range = 1000000-19999999
117 idmap config * : rangesize = 1000000
119 idmap config TRUSTED : backend = ad
120 idmap config TRUSTED : range = 50000 - 99999
121 idmap config TRUSTED : schema_mode = sfu
127 <title>AUTHOR</title>
130 The original Samba software and related utilities
131 were created by Andrew Tridgell. Samba is now developed
132 by the Samba Team as an Open Source project similar
133 to the way the Linux kernel is developed.