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<?xml version="1.0" encoding="iso-8859-1"?>
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<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
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<chapter id="ChangeNotes">
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<title>Important and Critical Change Notes for the Samba 3.x Series</title>
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Please read this chapter carefully before update or upgrading Samba. You should expect to find only critical
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or very important information here. Comprehensive change notes and guidance information can be found in the
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section <link linkend="upgrading-to-3.0">Updating and Upgrading Samba</link>.
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<title>Important Samba-3.2.x Change Notes</title>
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!!!!!!!!!!!!Add all critical update notes here!!!!!!!!!!!!!
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<title>Important Samba-3.0.x Change Notes</title>
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These following notes pertain in particular to Samba 3.0.23 through Samba 3.0.25c (or more recent 3.0.25
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update). Samba is a fluid and ever changing project. Changes throughout the 3.0.x series release are
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documented in this documention - See <link linkend="oldupdatenotes">Upgrading from Samba-2.x to Samba-3.0.25</link>.
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Sometimes it is difficult to figure out which part, or parts, of the HOWTO documentation should be updated to
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reflect the impact of new or modified features. At other times it becomes clear that the documentation is in
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need of being restructured.
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In recent times a group of Samba users has joined the thrust to create a new <ulink
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url="http://wiki.samba.org/">Samba Wiki</ulink> that is slated to become the all-singing and all-dancing
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new face of Samba documentation. Hopefully, the Wiki will benefit from greater community input and
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thus may be kept more up to date. Until that golden dream materializes and matures it is necessary to
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continue to maintain the HOWTO. This chapter will document major departures from earlier behavior until
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such time as the body of this HOWTO is restructured or modified.
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This chapter is new to the release of the HOWTO for Samba 3.0.23. It includes much of the notes provided
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in the <filename>WHATSNEW.txt</filename> file that is included with the Samba source code release tarball.
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<title>User and Group Changes</title>
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The change documented here affects unmapped user and group accounts only.
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<indexterm><primary>user</primary></indexterm>
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<indexterm><primary>group</primary></indexterm>
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<indexterm><primary>Relative Identifiers</primary><see>RID</see></indexterm>
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<indexterm><primary>net</primary><secondary>groupmap</secondary></indexterm>
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<indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>vampire</tertiary></indexterm>
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The user and group internal management routines have been rewritten to prevent overlaps of
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assigned Relative Identifiers (RIDs). In the past the has been a potential problem when
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either manually mapping Unix groups with the <command>net groupmap</command> command or
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when migrating a Windows domain to a Samba domain by executing:
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<command>net rpc vampire</command>.
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<indexterm><primary>SID</primary></indexterm>
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<indexterm><primary>SAM</primary></indexterm>
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<indexterm><primary>RID</primary></indexterm>
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<indexterm><primary>net</primary><secondary>getlocalsid</secondary></indexterm>
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Unmapped users are now assigned a SID in the <literal>S-1-22-1</literal> domain and unmapped
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groups are assigned a SID in the <literal>S-1-22-2</literal> domain. Previously they were
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assigned a RID within the SAM on the Samba server. For a domain controller this would have been under the
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authority of the domain SID where as on a member server or standalone server, this would have
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been under the authority of the local SAM (see the man page for <command>net getlocalsid</command>).
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<indexterm><primary>unmapped users</primary></indexterm>
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<indexterm><primary>unmapped groups</primary></indexterm>
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<indexterm><primary>SID</primary></indexterm>
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<indexterm><primary>NTFS</primary></indexterm>
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<indexterm><primary>GID</primary></indexterm>
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The result is that any unmapped users or groups on an upgraded Samba domain controller may
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be assigned a new SID. Because the SID rather than a name is stored in Windows security
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descriptors, this can cause a user to no longer have access to a resource for example if a
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file was copied from a Samba file server to a local Windows client NTFS partition. Any files
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stored on the Samba server itself will continue to be accessible because UNIX stores the UNIX
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GID and not the SID for authorization checks.
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An example helps to illustrate the change:
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<indexterm><primary>group mapping</primary></indexterm>
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<indexterm><primary>GID</primary></indexterm>
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<indexterm><primary>ACL</primary></indexterm>
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<indexterm><primary>SID</primary></indexterm>
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Assume that a group named <emphasis>developers</emphasis> exists with a UNIX GID of 782. In this
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case this group does not exist in Samba's group mapping table. It would be perfectly normal for
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this group to be appear in an ACL editor. Prior to Samba-3.0.23, the group SID might appear as
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<literal>S-1-5-21-647511796-4126122067-3123570092-2565</literal>.
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<indexterm><primary>SID</primary></indexterm>
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<indexterm><primary>NTFS</primary></indexterm>
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<indexterm><primary>access</primary></indexterm>
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<indexterm><primary>group permissions</primary></indexterm>
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With the release of Samba-3.0.23, the group SID would be reported as <literal>S-1-22-2-782</literal>. Any
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security descriptors associated with files stored on a Windows NTFS disk partition will not allow access based
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on the group permissions if the user was not a member of the
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<literal>S-1-5-21-647511796-4126122067-3123570092-2565</literal> group. Because this group SID is
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<literal>S-1-22-2-782</literal> and not reported in a user's token, Windows would fail the authorization check
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even though both SIDs in some respect refer to the same UNIX group.
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<indexterm><primary>group mapping</primary></indexterm>
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<indexterm><primary>SID</primary></indexterm>
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The workaround for versions of Samba prior to 3.0.23, is to create a manual domain group mapping
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entry for the group <emphasis>developers</emphasis> to point at the
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<literal>S-1-5-21-647511796-4126122067-3123570092-2565</literal> SID. With the release of Samba-3.0.23 this
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workaround is no longer needed.
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<title>Essential Group Mappings</title>
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Samba 3.0.x series releases before 3.0.23 automatically created group mappings for the essential Windows
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domain groups <literal>Domain Admins, Domain Users, Domain Guests</literal>. Commencing with Samba 3.0.23
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these mappings need to be created by the Samba administrator. Failure to do this may result in a failure to
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correctly authenticate and recoognize valid domain users. When this happens users will not be able to log onto
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Group mappings are essentail only if the Samba servers is running as a PDC/BDC. Stand-alone servers do not
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require these group mappings.
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The following mappings are required:
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<table frame="all" id="TOSH-domgroups">
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<title>Essential Domain Group Mappings</title>
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<tgroup align="center" cols="3">
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<row><entry>Domain Group</entry><entry>RID</entry><entry>Example UNIX Group</entry></row>
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<row><entry>Domain Admins</entry><entry>512</entry><entry>root</entry></row>
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<row><entry>Domain Users</entry><entry>513</entry><entry>users</entry></row>
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<row><entry>Domain Guests</entry><entry>514</entry><entry>nobody</entry></row>
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When the POSIX (UNIX) groups are stored in LDAP, it may be desirable to call these <literal>domadmins, domusers,
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domguests</literal> respectively.
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For further information regarding group mappings see <link linkend="groupmapping">Group Mapping: MS Windows
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<title>Passdb Changes</title>
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<indexterm><primary>backends</primary></indexterm>
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<indexterm><primary>GID</primary></indexterm>
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<indexterm><primary>SQL</primary></indexterm>
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<indexterm><primary>XML</primary></indexterm>
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The <smbconfoption name="passdb backend"/> parameter no longer accepts multiple passdb backends in a
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chained configuration. Also be aware that the SQL and XML based passdb modules have been
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removed in the Samba-3.0.23 release. More information regarding external support for a SQL
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passdb module can be found on the <ulink url="http://pdbsql.sourceforge.net/">pdbsql</ulink> web site.
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<title>Group Mapping Changes in Samba-3.0.23</title>
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<indexterm><primary>default mapping</primary></indexterm>
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<indexterm><primary>Domain Admins</primary></indexterm>
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<indexterm><primary>smbpasswd</primary></indexterm>
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<indexterm><primary>tdbsam</primary></indexterm>
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<indexterm><primary>passdb backend</primary></indexterm>
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<indexterm><primary>group mappings</primary></indexterm>
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<indexterm><primary>GID</primary></indexterm>
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<indexterm><primary>SID</primary></indexterm>
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<indexterm><primary>IDMAP</primary></indexterm>
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<indexterm><primary>winbindd</primary></indexterm>
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<indexterm><primary>domain groups</primary></indexterm>
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The default mapping entries for groups such as <literal>Domain Admins</literal> are no longer
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created when using an <literal>smbpasswd</literal> file or a <literal>tdbsam</literal> passdb
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backend. This means that it is necessary to explicitly execute the <command>net groupmap add</command>
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to create group mappings, rather than use the <command>net groupmap modify</command> method to create the
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Windows group SID to UNIX GID mappings. This change has no effect on winbindd's IDMAP functionality
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<title>LDAP Changes in Samba-3.0.23</title>
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<indexterm><primary>LDAP schema</primary></indexterm>
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<indexterm><primary>sambaSID</primary></indexterm>
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<indexterm><primary>OpenLDAP</primary></indexterm>
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<indexterm><primary>slapindex</primary></indexterm>
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<indexterm><primary>slapd.conf</primary></indexterm>
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There has been a minor update the Samba LDAP schema file. A substring matching rule has been
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added to the <literal>sambaSID</literal> attribute definition. For OpenLDAP servers, this
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will require the addition of <literal>index sambaSID sub</literal> to the
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<filename>slapd.conf</filename> configuration file. It will be necessary to execute the
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<command>slapindex</command> command after making this change. There has been no change to the
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actual data storage schema.