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">4.0</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 and for
56 non-domain well-known SIDs like Everyone (S-1-1-0) or Creator Owner (S-1-3-0).
57 A chosen list of well-known SIDs will be preallocated on first start
58 to create deterministic mappings for those.</para>
60 Thus the number of local users and groups that can be created is
61 limited by this option as well. If you plan to create a large amount
62 of local users or groups, you will need set this parameter accordingly.
64 <para>The default value is 100000.</para>
68 <term>read only = [ yes | no ]</term>
69 <listitem><para>Turn the module into read-only mode. No new ranges will be allocated
70 nor will new mappings be created in the idmap pool. Defaults to no.</para>
74 <term>ignore builtin = [ yes | no ]</term>
75 <listitem><para>Ignore any mapping requests for the BUILTIN domain.
76 Defaults to no.</para>
83 <title>THE MAPPING FORMULAS</title>
85 The Unix ID for a RID is calculated this way:
87 ID = IDMAP UID LOW VALUE + DOMAINRANGENUMBER * RANGESIZE + RID
91 Correspondingly, the formula for calculating the RID for a
92 given Unix ID is this:
94 RID = ID - IDMAP UID LOW VALUE - DOMAINRANGENUMBER * RANGESIZE
100 <title>EXAMPLES</title>
102 This example shows you the minimal configuration that will
103 work for the principial domain and 19 trusted domains.
112 idmap config * : backend = autorid
113 idmap config * : range = 1000000-1999999
118 This example shows how to configure idmap_autorid as default
119 for all domains with a potentially large amount of users
120 plus a specific configuration for a trusted domain
121 that uses the SFU mapping scheme. Please note that idmap
122 ranges and sfu ranges are not allowed to overlap.
131 idmap config * : backend = autorid
132 idmap config * : range = 1000000-19999999
133 idmap config * : rangesize = 1000000
135 idmap config TRUSTED : backend = ad
136 idmap config TRUSTED : range = 50000 - 99999
137 idmap config TRUSTED : schema_mode = sfu
143 <title>AUTHOR</title>
146 The original Samba software and related utilities
147 were created by Andrew Tridgell. Samba is now developed
148 by the Samba Team as an Open Source project similar
149 to the way the Linux kernel is developed.