tevent: Add an internal function tevent_epoll_set_panic_fallback().

[Samba.git] / docs-xml / Samba3-ByExample / SBE-UpgradingSamba.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
<chapter id="upgrades">
<title>Updating Samba-3</title>

<para>
<indexterm><primary>migrate</primary></indexterm>
<indexterm><primary>install</primary></indexterm>
It was a little difficult to select an appropriate title for this chapter.
From email messages on the Samba mailing lists it is clear that many people
consider the updating and upgrading of Samba to be a migration matter. Others
talk about migrating Samba servers when in fact the issue at hand is one of
installing a new Samba server to replace an older existing Samba server.
</para>

<para>
<indexterm><primary>smbpasswd</primary></indexterm>
<indexterm><primary>passdb backend</primary></indexterm>
There has also been much talk about migration of Samba-3 from an smbpasswd
passdb backend to the use of the tdbsam or ldapsam facilities that are new
to Samba-3.
</para>

<para>
Clearly, there is not a great deal of clarity in the terminology that various
people apply to these modes by which Samba servers are updated. This is further 
highlighted by an email posting that included the following neat remark:
</para>

<blockquote><para>
<indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>vampire</tertiary></indexterm>
I like the <quote>net rpc vampire</quote> on NT4, but that to my surprise does
not seem to work against a Samba PDC and, if addressed in the Samba to Samba
context in either book, I could not find it.
</para></blockquote>

<para>
<indexterm><primary>contributions</primary></indexterm>
So in response to the significant request for these situations to be better 
documented, this chapter has now been added. User contributions and documentation
of real-world experiences are a most welcome addition to this chapter.
</para>

<sect1>
<title>Introduction</title>

<para>
<indexterm><primary>update</primary></indexterm>
<indexterm><primary>upgrade</primary></indexterm>
<indexterm><primary>frustration</primary></indexterm>
A Windows network administrator explained in an email what changes he was
planning to make and followed with the question: <quote>Anyone done this
before?</quote> Many of us have upgraded and updated Samba without incident.
Others have experienced much pain and user frustration. So it is to be hoped
that the notes in this chapter will make a positive difference by assuring
that someone will be saved a lot of discomfort.
</para>

<para>
Before anyone commences an upgrade or an update of Samba, the one cardinal
rule that must be observed is: Backup all Samba configuration files in
case it is necessary to revert to the old version. Even if you do not like
this precautionary step, users will punish an administrator who
fails to take adequate steps to avoid situations that may inflict lost
productivity on them.
</para>

<warning><para>
<indexterm><primary>configuration files</primary></indexterm>
<indexterm><primary>down-grade</primary></indexterm>
Samba makes it possible to upgrade and update configuration files, but it
is not possible to downgrade the configuration files. Please ensure that
all configuration and control files are backed up to permit a down-grade
in the rare event that this may be necessary.
</para></warning>


<para>
<indexterm><primary>adequate precautions</primary></indexterm>
<indexterm><primary>precaution</primary></indexterm>
It is prudent also to backup all data files on the server before attempting
to perform a major upgrade. Many administrators have experienced the consequences
of failure to take adequate precautions. So what is adequate? That is simple!
If data is lost during an upgrade or update and it can not be restored,
the precautions taken were inadequate. If a backup was not needed, but was available,
caution was on the side of the victor.
</para>

        <sect2>
        <title>Cautions and Notes</title>

        <para>
        Someone once said, <quote>It is good to be sorry, but better never to need to be!</quote>
        These are wise words of advice to those contemplating a Samba upgrade or update.
        </para>

        <para>
        <indexterm><primary>update</primary></indexterm>
        <indexterm><primary>upgrade</primary></indexterm>
        <indexterm><primary>generation</primary></indexterm>
        This is as good a time as any to define the terms <constant>upgrade</constant> and
        <constant>update</constant>. The term <constant>upgrade</constant> refers to
        the installation of a version of Samba that is a whole generation or more ahead of
        that which is installed. Generations are indicated by the first digit of the version
        number. So far Samba has been released in generations 1.x, 2.x, 3.x, and currently 4.0
        is in development.
        </para>

        <para>
        <indexterm><primary>generation</primary></indexterm>
        The term <constant>update</constant> refers to a minor version number installation
        in place of one of the same generation. For example, updating from Samba 3.0.10 to 3.0.14
        is an update. The move from Samba 2.0.7 to 3.0.14 is an upgrade.
        </para>

        <para>
        <indexterm><primary>functional differences</primary></indexterm>
        While the use of these terms is an exercise in semantics, what needs to be realized
        is that there are major functional differences between a Samba 2.x release and a Samba
        3.0.x release. Such differences may require a significantly different approach to
        solving the same networking challenge and generally require careful review of the
        latest documentation to identify precisely how the new installation may need to be
        modified to preserve prior functionality.
        </para>

        <para>
        There is an old axiom that says, <quote>The greater the volume of the documentation,
        the greater the risk that noone will read it, but where there is no documentation,
        noone can read it!</quote> While true, some documentation is an evil necessity.
        It is hoped that this update to the documentation will avoid both extremes.
        </para>

        <sect3>
        <title>Security Identifiers (SIDs)</title>

        <para>
        <indexterm><primary>Windows</primary><secondary>NT</secondary></indexterm>
        <indexterm><primary>OS/2</primary></indexterm>
        <indexterm><primary>DOS</primary></indexterm>
        <indexterm><primary>SID</primary></indexterm>
        <indexterm><primary>networking</primary><secondary>client</secondary></indexterm>
        <indexterm><primary>security</primary><secondary>identifier</secondary></indexterm>
        Before the days of Windows NT and OS/2, every Windows and DOS networking client
        that used the SMB protocols was an entirely autonomous entity. There was no concept
        of a security identifier for a machine or a user outside of the username, the
        machine name, and the workgroup name. In actual fact, these were not security identifiers
        in the same context as the way that the SID is used since the development of
        Windows NT 3.10.
        </para>

        <para>
        <indexterm><primary>SessionSetUpAndX</primary></indexterm>
        <indexterm><primary>SMB</primary></indexterm>
        <indexterm><primary>CIFS</primary></indexterm>
        <indexterm><primary>SID</primary></indexterm>
        <indexterm><primary>username</primary></indexterm>
        <indexterm><primary>Windows</primary><secondary>client</secondary></indexterm>
        Versions of Samba prior to 1.9 did not make use of a SID. Instead they make exclusive use
        of the username that is embedded in the SessionSetUpAndX component of the connection
        setup process between a Windows client and an SMB/CIFS server. 
        </para>

        <para>
        <indexterm><primary>MACHINE.SID</primary></indexterm>
        <indexterm><primary>rpc</primary></indexterm>
        <indexterm><primary>security</primary></indexterm>
        Around November 1997 support was added to Samba-1.9 to handle the Windows security
        RPC-based protocols that implemented support for Samba to store a machine SID. This
        information was stored in a file called <filename>MACHINE.SID.</filename>
        </para>

        <para>
        <indexterm><primary>machine</primary></indexterm>
        <indexterm><primary>SID</primary></indexterm>
        <indexterm><primary>secrets.tdb</primary></indexterm>
        Within the lifetime of the early Samba 2.x series, the machine SID information was
        relocated into a tdb file called <filename>secrets.tdb</filename>, which is where
        it is still located in Samba 3.0.x along with other information that pertains to the
        local machine and its role within a domain security context.
        </para>

        <para>
        <indexterm><primary>server</primary><secondary>stand-alone</secondary></indexterm>
        <indexterm><primary>server</primary><secondary>domain member</secondary></indexterm>
        <indexterm><primary>DMS</primary></indexterm>
        <indexterm><primary>SAS</primary></indexterm>
        There are two types of SID, those pertaining to the machine itself and the domain to
        which it may belong, and those pertaining to users and groups within the security
        context of the local machine, in the case of standalone servers (SAS) and domain member
        servers (DMS).
        </para>

        <para>
        <indexterm><primary>smbd</primary></indexterm>
        <indexterm><primary>workgroup</primary></indexterm>
        <indexterm><primary>hostname</primary></indexterm>
        <indexterm><primary>daemon</primary></indexterm>
        <indexterm><primary>SID</primary></indexterm>
        <indexterm><primary>secrets.tdb</primary></indexterm>
        When the Samba <command>smbd</command> daemon is first started, if the <filename>secrets.tdb</filename>
        file does not exist, it is created at the first client connection attempt. If this file does
        exist, <command>smbd</command> checks that there is a machine SID (if it is a domain controller,
        it searches for the domain SID). If <command>smbd</command> does not find one for the current
        name of the machine or for the current name of the workgroup, a new SID will be generated and
        then written to the <filename>secrets.tdb</filename> file. The SID is generated in a nondeterminative
        manner. This means that each time it is generated for a particular combination of machine name
        (hostname) and domain name (workgroup), it will be different.
        </para>

        <para>
        <indexterm><primary>ACL</primary></indexterm>
        The SID is the key used by MS Windows networking for all networking operations. This means
        that when the machine or domain SID changes, all security-encoded objects such as profiles
        and ACLs may become unusable.
        </para>

        <note><para>
        It is of paramount importance that the machine and domain SID be backed up so that in
        the event of a change of hostname (machine name) or domain name (workgroup) the SID can
        be restored to its previous value.
        </para></note>

        <para>
        <indexterm><primary>domain controller</primary></indexterm>
        <indexterm><primary>PDC</primary></indexterm>
        <indexterm><primary>BDC</primary></indexterm>
        <indexterm><primary>domain SID</primary></indexterm>
        <indexterm><primary>hostname</primary></indexterm>
        <indexterm><primary>computer name</primary></indexterm>
        <indexterm><primary>netbios name</primary></indexterm>
        <indexterm><primary>stand-alone server</primary></indexterm>
        <indexterm><primary>SAS</primary></indexterm>
        <indexterm><primary>SID</primary></indexterm>
        In Samba-3 on a domain controller (PDC or BDC), the domain name controls the domain
        SID. On all prior versions the hostname (computer name, or NetBIOS name) controlled
        the SID. On a standalone server the hostname still controls the SID.
        </para>

        <para>
        <indexterm><primary>net</primary><secondary>getlocalsid</secondary></indexterm>
        <indexterm><primary>net</primary><secondary>setlocalsid</secondary></indexterm>
        The local machine SID can be backed up using this procedure (Samba-3):
<screen>
&rootprompt; net getlocalsid > /etc/samba/my-local-SID
</screen>
        The contents of the file <filename>/etc/samba/my-local-SID</filename> will be:
<screen>
SID for domain FRODO is: S-1-5-21-726309263-4128913605-1168186429
</screen>
        This SID can be restored by executing:
<screen>
&rootprompt; net setlocalsid S-1-5-21-726309263-4128913605-1168186429
</screen>
        </para>

        <para>
        Samba 1.9.x stored the machine SID in the the file <filename>/etc/MACHINE.SID</filename>
        from which it could be recovered and stored into the <filename>secrets.tdb</filename> file
        using the procedure shown above.
        </para>

        <para>
        Where the <filename>secrets.tdb</filename> file exists and a version of Samba 2.x or later
        has been used, there is no specific need to go through this update process. Samba-3 has the
        ability to read the older tdb file and to perform an in-situ update to the latest tdb format.
        This is not a reversible process &smbmdash; it is a one-way upgrade.
        </para>

        <para>
        <indexterm><primary>smbpasswd</primary></indexterm>
        In the course of the Samba 2.0.x series the <command>smbpasswd</command> was modified to
        permit the domain SID to be captured to the <filename>secrets.tdb</filename> file by executing:
<screen>
&rootprompt; smbpasswd -S PDC -Uadministrator%password
</screen>
        </para>

        <para>
        The release of the Samba 2.2.x series permitted the SID to be obtained by executing:
<screen>
&rootprompt; smbpasswd -S PDC -Uadministrator%password
</screen>
        from which the SID could be copied to a file and then written to the Samba-2.2.x
        <filename>secrets.tdb</filename> file by executing:
<screen>
&rootprompt; smbpasswd -W S-1-5-21-726309263-4128913605-1168186429
</screen>
        </para>

        <para>
        <indexterm><primary>rpcclient</primary></indexterm>
        <indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>info</tertiary></indexterm>
        Domain security information, which includes the domain SID, can be obtained from Samba-2.2.x
        systems by executing:
<screen>
&rootprompt; rpcclient hostname lsaquery -Uroot%password
</screen>
        This can also be done with Samba-3 by executing:
<screen>
&rootprompt; net rpc info -Uroot%password
Domain Name: MIDEARTH
Domain SID: S-1-5-21-726309263-4128913605-1168186429
Sequence number: 1113415916
Num users: 4237
Num domain groups: 86
Num local groups: 0
</screen>
        It is a very good practice to store this SID information in a safely kept file, just in
        case it is ever needed at a later date.
        </para>

        <para>
        <indexterm><primary>passdb backend</primary></indexterm>
        <indexterm><primary>LDAP</primary></indexterm>
        <indexterm><primary>SID</primary></indexterm>
        Take note that the domain SID is used extensively in Samba. Where LDAP is used for the
        <parameter>passdb backend</parameter>, all user, group, and trust accounts are encoded
        with the domain SID. This means that if the domain SID changes for any reason, the entire
        Samba environment can become broken and require extensive corrective action if the 
        original SID cannot be restored. Fortunately, it can be recovered from a dump of the
        LDAP database. A dump of the LDAP directory database can be obtained by executing:
<screen>
&rootprompt; slapcat -v -l filename.ldif
</screen>
        </para>

        <para>
        <indexterm><primary>SID</primary></indexterm>
        <indexterm><primary>profiles</primary></indexterm>
        <indexterm><primary>RPM</primary></indexterm>
        When the domain SID has changed, roaming profiles cease to be functional. The recovery
        of roaming profiles necessitates resetting of the domain portion of the user SID
        that owns the profile. This is encoded in the <filename>NTUser.DAT</filename> and can be
        updated using the Samba <command>profiles</command> utility. Please be aware that not all
        Linux distributions of the Samba RPMs include this essential utility. Please do not
        complain to the Samba Team if this utility is missing; that issue that must be
        addressed to the creator of the RPM package. The Samba Team do their best to make
        available all the tools needed to manage a Samba-based Windows networking environment.
        </para>

        </sect3>

        <sect3>
        <title>Change of hostname</title>

        <para>
        <indexterm><primary>netbios</primary><secondary>machine  name</secondary></indexterm>
        <indexterm><primary>netbios name</primary></indexterm>
        Samba uses two methods by which the primary NetBIOS machine name (also known as a computer
        name or the hostname) may be determined: If the &smb.conf; file contains a
        <parameter>netbios name</parameter> entry, its value will be used directly. In the absence
        of such an entry, the UNIX system hostname will be used.
        </para>

        <para>
        Many sites have become victims of lost Samba functionality because the UNIX system
        hostname was changed for one reason or another. Such a change will cause a new machine
        SID to be generated. If this happens on a domain controller, it will also change the
        domain SID. These SIDs can be updated (restored) using the procedure outlined previously.
        </para>

        <note><para>
        Do NOT change the hostname or the <parameter>netbios name</parameter>. If this
        is changed, be sure to reset the machine SID to the original setting. Otherwise
        there may be serious interoperability and/or operational problems.
        </para></note>

        </sect3>

        <sect3>
        <title>Change of Workgroup (Domain) Name</title>

        <para>
        <indexterm><primary>workgroup</primary></indexterm>
        The domain name of a Samba server is identical to the workgroup name and is
        set in the &smb.conf; file using the <parameter>workgroup</parameter> parameter.
        This has been consistent throughout the history of Samba and across all versions.
        </para>

        <para>
        <indexterm><primary>SID</primary></indexterm>
        Be aware that when the workgroup name is changed, a new SID will be generated.
        The old domain SID can be reset using the procedure outlined earlier in this chapter.
        </para>

        </sect3>

        <sect3 id="sbeug1">
        <title>Location of config files</title>

        <para>
        The Samba-Team has maintained a constant default location for all Samba control files
        throughout the life of the project. People who have produced binary packages of Samba
        have varied the location of the Samba control files. This has led to some confusion
        for network administrators.
        </para>

        <para>
        <indexterm><primary>directory</primary></indexterm>
        The Samba 1.9.x &smb.conf; file may be found either in the <filename>/etc</filename>
        directory or in <filename>/usr/local/samba/lib</filename>.
        </para>

        <para>
        During the life of the Samba 2.x release, the &smb.conf; file was relocated
        on Linux systems to the <filename>/etc/samba</filename> directory where it
        remains located also for Samba 3.0.x installations.
        </para>

        <para>
        <indexterm><primary>secrets.tdb</primary></indexterm>
        Samba 2.x introduced the <filename>secrets.tdb</filename> file that is also stored in the
        <filename>/etc/samba</filename> directory, or in the <filename>/usr/local/samba/lib</filename>
        directory subsystem.
        </para>

        <para>
        <indexterm><primary>smbd</primary></indexterm>
        The location at which <command>smbd</command> expects to find all configuration and control
        files is determined at the time of compilation of Samba. For versions of Samba prior to
        3.0, one way to find the expected location of these files is to execute:
<screen>
&rootprompt; strings /usr/sbin/smbd | grep conf
&rootprompt; strings /usr/sbin/smbd | grep secret
&rootprompt; strings /usr/sbin/smbd | grep smbpasswd
</screen>
        Note: The <command>smbd</command> executable may be located in the path
        <filename>/usr/local/samba/sbin</filename>.
        </para>

        <para>
        <indexterm><primary>compile-time</primary></indexterm>
        Samba-3 provides a neat new way to track the location of all control files as well as to
        find the compile-time options used as the Samba package was built. Here  is how the dark
        secrets of the internals of the location of control files within Samba executables can
        be uncovered:
<screen>
&rootprompt; smbd -b | less
Build environment:
   Built by:    root@frodo
   Built on:    Mon Apr 11 20:23:27 MDT 2005
   Built using: gcc
   Build host:  Linux frodo 2.6...
   SRCDIR:      /usr/src/packages/BUILD/samba-3.0.20/source
   BUILDDIR:    /usr/src/packages/BUILD/samba-3.0.20/source

Paths:
   SBINDIR: /usr/sbin
   BINDIR: /usr/bin
   SWATDIR: /usr/share/samba/swat
   CONFIGFILE: /etc/samba/smb.conf
   LOGFILEBASE: /var/log/samba
   LMHOSTSFILE: /etc/samba/lmhosts
   LIBDIR: /usr/lib/samba
   SHLIBEXT: so
   LOCKDIR: /var/lib/samba
   PIDDIR: /var/run/samba
   SMB_PASSWD_FILE: /etc/samba/smbpasswd
   PRIVATE_DIR: /etc/samba
 ... 
</screen>
        </para>

        <para>
        <indexterm><primary></primary></indexterm>
        It is important that both the &smb.conf; file and the <filename>secrets.tdb</filename>
        be backed up before attempting any upgrade. The <filename>secrets.tdb</filename> file
        is version-encoded, and therefore a newer version may not work with an older version
        of Samba. A backup means that it is always possible to revert a failed or problematic
        upgrade.
        </para>

        </sect3>

        <sect3>
        <title>International Language Support</title>

        <para>
        <indexterm><primary>unicode</primary></indexterm>
        <indexterm><primary>character set</primary></indexterm>
        <indexterm><primary>codepage</primary></indexterm>
        <indexterm><primary>internationalization</primary></indexterm>
        Samba-2.x had no support for Unicode; instead, all national language character-set support in file names
        was done using particular locale codepage mapping techniques. Samba-3 supports Unicode in file names, thus
        providing true internationalization support.
        </para>

        <para>
        <indexterm><primary>8-bit</primary></indexterm>
        Non-English users whose national language character set has special characters and who upgrade naively will 
        find that many files that have the special characters in the file name will see them garbled and jumbled up.
        This typically happens with umlauts and accents because these characters were particular to the codepage
        that was in use with Samba-2.x using an 8-bit encoding scheme.
        </para>

        <para>
        <indexterm><primary>UTF-8</primary></indexterm>
        Files that are created with Samba-3 will use UTF-8 encoding. Should the file system ever end up with a
        mix of codepage (unix charset)-encoded file names and UTF-8-encoded file names, the mess will take some
        effort to set straight.
        </para>

        <para>
        <indexterm><primary>convmv</primary></indexterm>
        A very helpful tool is available from Bjorn Jacke's <ulink url="http://j3e.de/linux/convmv/">convmv</ulink>
        work. Convmv is a tool that can be used to convert file and directory names from one encoding method to
        another. The most common use for this tool is to convert locale-encoded files to UTF-8 Unicode encoding.
        </para>

        </sect3>

        <sect3>
        <title>Updates and Changes in Idealx smbldap-tools</title>

        <para>
        The smbldap-tools have been maturing rapidly over the past year. With maturation comes change.
        The location of the <filename>smbldap.conf</filename> and the <filename>smbldap_bind.conf</filename>
        configuration files have been moved from the directory <filename>/etc/smbldap-tools</filename> to
        the new location of <filename>/etc/opt/IDEALX/smblda-tools</filename> directory.
        </para>

        <para>
        The smbldap-tools maintains an entry in the LDAP directory in which it stores the next
        values that should be used for UID and GID allocation for POSIX accounts that are created
        using this tool. The DIT location of these values has changed recently. The original
        <constant>sambaUnixIdPooldn object</constant> entity was stored in a directory entry (DIT object)
        called <constant>NextFreeUnixId</constant>, this has been changed to the DIT object
        <constant>sambaDomainName</constant>. Anyone who updates from an older version to the
        current release should note that the information stored under <constant>NextFreeUnixId</constant>
        must now be relocated to the DIT object <constant>sambaDomainName</constant>.
        </para>

        </sect3>

        </sect2>

</sect1>

<sect1>
<title>Upgrading from Samba 1.x and 2.x to Samba-3</title>

<para>
Sites that are being upgraded from Samba-2 (or earlier versions) to Samba-3
may experience little difficulty or may require a lot of effort, depending
on the complexity of the configuration. Samba-1.9.x upgrades to Samba-3 will
generally be simple and straightforward, although no upgrade should be
attempted without proper planning and preparation.
</para>

<para>
There are two basic modes of use of Samba versions prior to Samba-3. The first
does not use LDAP, the other does. Samba-1.9.x did not provide LDAP support.
Samba-2.x could be compiled with LDAP support.
</para>

        <sect2 id="sbeug2">
        <title>Samba 1.9.x and 2.x Versions Without LDAP</title>

        <para>
        Where it is necessary to upgrade an old Samba installation to Samba-3,
        the following procedure can be followed:
        </para>

        <procedure>
        <title>Upgrading from a Pre-Samba-3 Version</title>

                <step><para>
                <indexterm><primary>winbindd</primary></indexterm>
                <indexterm><primary>smbd</primary></indexterm>
                <indexterm><primary>nmbd</primary></indexterm>
                Stop Samba. This can be done using the appropriate system tool
                that is particular for each operating system or by executing the
                <command>kill</command> command on <command>smbd</command>,
                <command>nmbd</command>, and <command>winbindd</command>.
                </para></step>

                <step><para>
                Find the location of the Samba &smb.conf; file and back it up to a
                safe location.
                </para></step>

                <step><para>
                Find the location of the <filename>smbpasswd</filename> file and
                back it up to a safe location.
                </para></step>

                <step><para>
                Find the location of the <filename>secrets.tdb</filename> file and
                back it up to a safe location.
                </para></step>

                <step><para>
                <indexterm><primary>lock directory</primary></indexterm>
                <indexterm><primary>/usr/local/samba/var/locks</primary></indexterm>
                <indexterm><primary>/var/cache/samba</primary></indexterm>
                <indexterm><primary>/var/lib/samba</primary></indexterm>
                Find the location of the lock directory. This is the directory
                in which Samba stores all its tdb control files. The default
                location used by the Samba Team is in
                <filename>/usr/local/samba/var/locks</filename> directory,
                but on Linux systems the old location was under the
                <filename>/var/cache/samba</filename> directory. However, the
                Linux Standards Base specified location is now under the
                <filename>/var/lib/samba</filename> directory. Copy all the
                tdb files to a safe location.
                </para></step>

                <step><para>
                <indexterm><primary>RPM</primary></indexterm>
                It is now safe to upgrade the Samba installation. On Linux systems
                it is not necessary to remove the Samba RPMs because a simple
                upgrade installation will automatically remove the old files.
                </para>

                <para>
                On systems that do not support a reliable package management system
                it is advisable either to delete the Samba old installation or to
                move it out of the way by renaming the directories that contain the
                Samba binary files.
                </para></step>

                <step><para>
                When the Samba upgrade has been installed, the first step that should
                be completed is to identify the new target locations for the control
                files. Follow the steps shown in <link linkend="sbeug1"/> to locate
                the correct directories to which each control file must be moved.
                </para></step>

                <step><para>
                Do not change the hostname.
                </para></step>

                <step><para>
                Do not change the workgroup name.
                </para></step>

                <step><para>
                <indexterm><primary>testparm</primary></indexterm>
                Execute the <command>testparm</command> to validate the &smb.conf; file.
                This process will flag any parameters that are no longer supported.
                It will also flag configuration settings that may be in conflict.
                </para>

                <para>
                One solution that may be used to clean up and to update the &smb.conf;
                file involves renaming it to <filename>smb.conf.master</filename> and 
                then executing the following:
<screen>
&rootprompt; cd /etc/samba
&rootprompt; testparm -s smb.conf.master &gt; smb.conf
</screen>
        <indexterm><primary>stripped</primary></indexterm>
                The resulting &smb.conf; file will be stripped of all comments
                and of all nonconforming configuration settings.
                </para></step>

                <step><para>
                <indexterm><primary>winbindd</primary></indexterm>
                It is now safe to start Samba using the appropriate system tool.
                Alternately, it is possible to just execute <command>nmbd</command>,
                <command>smbd</command>, and <command>winbindd</command> for the command
                line while logged in as the root user.
                </para></step>

        </procedure>

        </sect2>

        <sect2>
        <title>Applicable to All Samba 2.x to Samba-3 Upgrades</title>

        <para>
        <indexterm><primary>PDC</primary></indexterm>
        <indexterm><primary>domain controller</primary></indexterm>
        <indexterm><primary>inter-domain</primary></indexterm>
        Samba 2.x servers that were running as a domain controller (PDC)
        require changes to the configuration of the scripting interface
        tools that Samba uses to perform OS updates for
        users, groups, and trust accounts (machines and interdomain).
        </para>

        <para>
        <indexterm><primary>parameters</primary></indexterm>
        The following parameters are new to Samba-3 and should be correctly configured.
        Please refer to <link linkend="secure"/> through <link linkend="net2000users"/>
        in this book for examples of use of the new parameters shown here:
        <indexterm><primary>add group script</primary></indexterm>
        <indexterm><primary>add machine script</primary></indexterm>
        <indexterm><primary>add user to group script</primary></indexterm>
        <indexterm><primary>delete group script</primary></indexterm>
        <indexterm><primary>delete user from group script</primary></indexterm>
        <indexterm><primary>set primary group script</primary></indexterm>
        <indexterm><primary>passdb backend</primary></indexterm>
        </para>

        <para>
        <simplelist>
                <member>add group script</member>
                <member>add machine script</member>
                <member>add user to group script</member>
                <member>delete group script</member>
                <member>delete user from group script</member>
                <member>passdb backend</member>
                <member>set primary group script</member>
                </simplelist>
        </para>

        <para>
        <indexterm><primary>add machine script</primary></indexterm>
        <indexterm><primary>add user script</primary></indexterm>
        The <parameter>add machine script</parameter> functionality was previously
        handled by the <parameter>add user script</parameter>, which in Samba-3 is
        used exclusively to add user accounts.
        </para>

        <para>
        <indexterm><primary>passdb backend</primary></indexterm>
        <indexterm><primary>smbpasswd</primary></indexterm>
        <indexterm><primary>tdbsam</primary></indexterm>
        <indexterm><primary>useradd</primary></indexterm>
        <indexterm><primary>usermod</primary></indexterm>
        <indexterm><primary>userdel</primary></indexterm>
        <indexterm><primary>groupadd</primary></indexterm>
        <indexterm><primary>groupmod</primary></indexterm>
        <indexterm><primary>groupdel</primary></indexterm>
        Where the <parameter>passdb backend</parameter> used is either <constant>smbpasswd</constant>
        (the default) or the new <constant>tdbsam</constant>, the system interface scripts
        are typically used. These involve use of OS tools such as <command>useradd</command>,
        <command>usermod</command>, <command>userdel</command>, <command>groupadd</command>,
        <command>groupmod</command>, <command>groupdel</command>, and so on.
        </para>

        <para>
        <indexterm><primary>passdb backend</primary></indexterm>
        <indexterm><primary>LDAP</primary></indexterm>
        <indexterm><primary>Idealx</primary></indexterm>
        Where the <parameter>passdb backend</parameter> makes use of an LDAP directory,
        it is necessary either to use the <constant>smbldap-tools</constant> provided
        by Idealx or to use an alternate toolset provided by a third
        party or else home-crafted to manage the LDAP directory accounts.
        </para>

        </sect2>

        <sect2>
        <title>Samba-2.x with LDAP Support</title>

        <para>
        Samba version 2.x could be compiled for use either with or without LDAP.
        The LDAP control settings in the &smb.conf; file in this old version are
        completely different (and less complete) than they are with Samba-3. This
        means that after migrating the control files, it is necessary to reconfigure
        the LDAP settings entirely.
        </para>

        <para>
        Follow the procedure outlined in <link linkend="sbeug2"/> to affect a migration
        of all files to the correct locations.
        </para>

        <para>
        <indexterm><primary>schema</primary></indexterm>
        <indexterm><primary>WHATSNEW.txt</primary></indexterm>
        The Samba SAM schema required for Samba-3 is significantly different from that
        used with Samba 2.x. This means that the LDAP directory must be updated
        using the procedure outlined in the Samba WHATSNEW.txt file that accompanies
        all releases of Samba-3. This information is repeated here directly from this
        file:
<screen>
This is an extract from the Samba-3.0.x WHATSNEW.txt file:
==========================================================
Changes in Behavior
-------------------

The following issues are known changes in behavior between Samba 2.2 and
Samba 3.0 that may affect certain installations of Samba.

  1)  When operating as a member of a Windows domain, Samba 2.2 would
      map any users authenticated by the remote DC to the 'guest account'
      if a uid could not be obtained via the getpwnam() call.  Samba 3.0
      rejects the connection as NT_STATUS_LOGON_FAILURE.  There is no
      current work around to re-establish the 2.2 behavior.

  2)  When adding machines to a Samba 2.2 controlled domain, the
      'add user script' was used to create the UNIX identity of the
      machine trust account.  Samba 3.0 introduces a new 'add machine
      script' that must be specified for this purpose.  Samba 3.0 will
      not fall back to using the 'add user script' in the absence of
      an 'add machine script'

######################################################################
Passdb Backends and Authentication
##################################

There have been a few new changes that Samba administrators should be
aware of when moving to Samba 3.0.

  1) encrypted passwords have been enabled by default in order to
     inter-operate better with out-of-the-box Windows client
     installations.  This does mean that either (a) a samba account
     must be created for each user, or (b) 'encrypt passwords = no'
     must be explicitly defined in smb.conf.

  2) Inclusion of new 'security = ads' option for integration
     with an Active Directory domain using the native Windows
     Kerberos 5 and LDAP protocols.

     MIT kerberos 1.3.1 supports the ARCFOUR-HMAC-MD5 encryption
     type which is necessary for servers on which the
     administrator password has not been changed, or kerberos-enabled
     SMB connections to servers that require Kerberos SMB signing.
     Besides this one difference, either MIT or Heimdal Kerberos
     distributions are usable by Samba 3.0.


Samba 3.0 also includes the possibility of setting up chains
of authentication methods (auth methods) and account storage
backends (passdb backend).  Please refer to the smb.conf(5)
man page for details.  While both parameters assume sane default
values, it is likely that you will need to understand what the
values actually mean in order to ensure Samba operates correctly.

The recommended passdb backends at this time are

  * smbpasswd - 2.2 compatible flat file format
  * tdbsam - attribute rich database intended as an smbpasswd
    replacement for stand alone servers
  * ldapsam - attribute rich account storage and retrieval
    backend utilizing an LDAP directory.

Certain functions of the smbpasswd(8) tool have been split between the
new smbpasswd(8) utility, the net(8) tool, and the new pdbedit(8)
utility.  See the respective man pages for details.

New Suffix for Searching
------------------------

The following new smb.conf parameters have been added to aid in directing
certain LDAP queries when 'passdb backend = ldapsam://...' has been
specified.

  * ldap suffix         - used to search for user and computer accounts
  * ldap user suffix    - used to store user accounts
  * ldap machine suffix - used to store machine trust accounts
  * ldap group suffix   - location of posixGroup/sambaGroupMapping entries
  * ldap idmap suffix   - location of sambaIdmapEntry objects

If an 'ldap suffix' is defined, it will be appended to all of the
remaining sub-suffix parameters.  In this case, the order of the suffix
listings in smb.conf is important.  Always place the 'ldap suffix' first
in the list.

Due to a limitation in Samba's smb.conf parsing, you should not surround
the DN's with quotation marks.
</screen>
        </para>

        </sect2>

</sect1>

<sect1>
<title>Updating a Samba-3 Installation</title>

<para>
The key concern in this section is to deal with the changes that have been
affected in Samba-3 between the Samba-3.0.0 release and the current update.
Network administrators have expressed concerns over the steps that should be
taken to update Samba-3 versions.
</para>

<para>
<indexterm><primary>control files</primary></indexterm>
The information in <link linkend="sbeug1"/> would not be necessary if every
person who has ever produced Samba executable (binary) files could agree on
the preferred location of the &smb.conf; file and other Samba control files.
Clearly, such agreement is further away than a pipedream.
</para>

<para>
<indexterm><primary>vendors</primary></indexterm>
Vendors and packagers who produce Samba binary installable packages do not,
as a rule, use the default paths used by the Samba-Team for the location of
the binary files, the &smb.conf; file, and the Samba control files (tdb's
as well as files such as <filename>secrets.tdb</filename>). This means that
the network or UNIX administrator who sets out to build the Samba executable
files from the Samba tarball must take particular care. Failure to take care
will result in both the original vendor's version of Samba remaining installed
and the new version being installed in the default location used
by the Samba-Team. This can lead to confusion and to much lost time as the
uninformed administrator deals with apparent failure of the update to take
effect.
</para>

<para>
<indexterm><primary>packages</primary></indexterm>
The best advice for those lacking in code compilation experience is to use
only vendor (or Samba-Team) provided binary packages. The Samba packages
that are provided by the Samba-Team are generally built to use file paths
that are compatible with the original OS vendor's practices.
</para>

<para>
<indexterm><primary>binary package</primary></indexterm>
<indexterm><primary>binary files</primary></indexterm>
If you are not sure whether a binary package complies with the OS
vendor's practices, it is better to ask the package maintainer via
email than to waste much time dealing with the nuances.
Alternately, just diagnose the paths specified by the binary files following
the procedure outlined above.
</para>

        <sect2>
        <title>Samba-3 to Samba-3 Updates on the Same Server</title>

        <para>
        The guidance in this section deals with updates to an existing
        Samba-3 server installation.
        </para>

        <sect3>
        <title>Updating from Samba Versions Earlier than 3.0.5</title>

        <para>
        With the provision that the binary Samba-3 package has been built
        with the same path and feature settings as the existing Samba-3
        package that is being updated, an update of Samba-3 versions 3.0.0
        through 3.0.4 can be updated to 3.0.5 without loss of functionality
        and without need to change either the &smb.conf; file or, where
        used, the LDAP schema.
        </para>

        </sect3>

        <sect3>
        <title>Updating from Samba Versions between 3.0.6 and 3.0.10</title>

        <para>
        <indexterm><primary>schema</primary></indexterm>
        <indexterm><primary>LDAP</primary><secondary>schema</secondary></indexterm>
        When updating versions of Samba-3 prior to 3.0.6 to 3.0.6 through 3.0.10,
        it is necessary only to update the LDAP schema (where LDAP is used).
        Always use the LDAP schema file that is shipped with the latest Samba-3
        update.
        </para>

        <para>
        <indexterm><primary>ldapsam</primary></indexterm>
        <indexterm><primary>tdbsam</primary></indexterm>
        <indexterm><primary>passdb backend</primary></indexterm>
        Samba-3.0.6 introduced the ability to remember the last <emphasis>n</emphasis> number
        of passwords a user has used. This information will work only with
        the <constant>tdbsam</constant> and <constant>ldapsam</constant>
        <parameter>passdb backend</parameter> facilities.
        </para>

        <para>
        After updating the LDAP schema, do not forget to re-index the LDAP database.
        </para>

        </sect3>

        <sect3>
        <title>Updating from Samba Versions after 3.0.6 to a Current Release</title>

        <para>
        <indexterm><primary>winbindd</primary></indexterm>
        Samba-3.0.8 introduced changes in how the <parameter>username map</parameter>
        behaves. It also included a change in behavior of <command>winbindd</command>.
        Please refer to the man page for &smb.conf; before implementing any update
        from versions prior to 3.0.8 to a current version.
        </para>

        <para>
        <indexterm><primary>privileges</primary></indexterm>
        In Samba-3.0.11 a new privileges interface was implemented. Please
        refer to <link linkend="sbehap-ppc"/> for information regarding this new
        feature. It is not necessary to implement the privileges interface, but it
        is one that has been requested for several years and thus may be of interest
        at your site.
        </para>

        <para>
        In Samba-3.0.11 there were some functional changes to the <parameter>ldap user
        suffix</parameter> and to the <parameter>ldap machine suffix</parameter> behaviors.
        The following information has been extracted from the WHATSNEW.txt file from this
        release:
<screen>
============
LDAP Changes
============

If "ldap user suffix" or "ldap machine suffix" are defined in
smb.conf, all user-accounts must reside below the user suffix,
and all machine and inter-domain trust-accounts must be located
below the machine suffix.  Previous Samba releases would fall
back to searching the 'ldap suffix' in some cases.
</screen>
        </para>

        </sect3>
        </sect2>

        <sect2>
        <title>Migrating Samba-3 to a New Server</title>

        <para>
        The two most likely candidates for replacement of a server are
        domain member servers and domain controllers. Each needs to be
        handled slightly differently.
        </para>

        <sect3>
        <title>Replacing a Domain Member Server</title>

        <para>
        <indexterm><primary>DMS</primary></indexterm>
        Replacement of a domain member server should be done
        using the same procedure as outlined in <link linkend="unixclients"/>.
        </para>

        <para>
        Usually the new server will be introduced with a temporary name. After
        the old server data has been migrated to the new server, it is customary
        that the new server be renamed to that of the old server. This will
        change its SID and will necessitate rejoining to the domain.
        </para>

        <para>
        <indexterm><primary>smbd</primary></indexterm>
        <indexterm><primary>nmbd</primary></indexterm>
        <indexterm><primary>winbindd</primary></indexterm>
        <indexterm><primary>wins.dat</primary></indexterm>
        <indexterm><primary>browse.dat</primary></indexterm>
        <indexterm><primary>resolution</primary></indexterm>
        Following a change of hostname (NetBIOS name) it is a good idea on all servers
        to shut down the Samba <command>smbd</command>, <command>nmbd</command>, and
        <command>winbindd</command> services, delete the <filename>wins.dat</filename>
        and <filename>browse.dat</filename> files, then restart Samba. This will ensure
        that the old name and IP address information is no longer able to interfere with
        name to IP address resolution.  If this is not done, there can be temporary name
        resolution problems. These problems usually clear within 45 minutes of a name
        change, but can persist for a longer period of time.
        </para>

        <para>
        <indexterm><primary>DMS</primary></indexterm>
        <indexterm><primary>/etc/passwd</primary></indexterm>
        <indexterm><primary>/etc/shadow</primary></indexterm>
        <indexterm><primary>/etc/group</primary></indexterm>
        If the old domain member server had local accounts, it is necessary to create
        on the new domain member server the same accounts with the same UID and GID
        for each account. Where the <parameter>passdb backend</parameter> database
        is stored in the <constant>smbpasswd</constant> or in the
        <constant>tdbsam</constant> format, the user and group account information
        for UNIX accounts that match the Samba accounts will reside in the system
        <filename>/etc/passwd</filename>, <filename>/etc/shadow</filename>, and
        <filename>/etc/group</filename> files. In this case, be sure to copy these
        account entries to the new target server.
        </para>

        <para>
        <indexterm><primary>nss_ldap</primary></indexterm>
        Where the user accounts for both UNIX and Samba are stored in LDAP, the new
        target server must be configured to use the <command>nss_ldap</command> tool set.
        This will automatically ensure that the appropriate user entities are
        available on the new server.
        </para>

        </sect3>

        <sect3>
        <title>Replacing a Domain Controller</title>

        <para>
        <indexterm><primary>domain</primary><secondary>controller</secondary></indexterm>
        In the past, people who replaced a Windows NT4 domain controller typically
        installed a new server, created printers and file shares on it, then migrate across
        all data that was destined to reside on it. The same can of course be done with
        Samba.
        </para>

        <para>
        From recent mailing list postings it would seem that some administrators
        have the intent to just replace the old Samba server with a new one with
        the same name as the old one. In this case, simply follow the same process
        as for upgrading a Samba 2.x system and do the following:
        </para>

        <itemizedlist>
                <listitem><para>
                Where UNIX (POSIX) user and group accounts are stored in the system
                <filename>/etc/passwd</filename>, <filename>/etc/shadow</filename>, and 
                <filename>/etc/group</filename> files, be sure to add the same accounts
                with identical UID and GID values for each user.
                </para>

                <para>
                Where LDAP is used, if the new system is intended to be the LDAP server,
                migrate it across by configuring the LDAP server 
                (<filename>/etc/openldap/slapd.conf</filename>). The directory can
                be populated either initially by setting this LDAP server up as a slave or
                by dumping the data from the old LDAP server using the <command>slapcat</command>
                command and then reloading the same data into the new LDAP server using the
                <command>slapadd</command> command. Do not forget to install and configure
                the <command>nss_ldap</command> tool and the <filename>/etc/nsswitch.conf</filename>
                (as shown in <link linkend="happy"/>).
                </para></listitem>

                <listitem><para>
                Copy the &smb.conf; file from the old server to the new server into the correct
                location as indicated previously in this chapter.
                </para></listitem>

                <listitem><para>
                Copy the <filename>secrets.tdb</filename> file, the <filename>smbpasswd</filename>
                file (if it is used), the <filename>/etc/samba/passdb.tdb</filename> file (only
                used by the <constant>tdbsam</constant> backend), and all the tdb control files
                from the old system to the correct location on the new system.
                </para></listitem>

                <listitem><para>
                Before starting the Samba daemons, verify that the hostname of the new server
                is identical to that of the old one. Note: The IP address can be different
                from that of the old server.
                </para></listitem>

                <listitem><para>
                Copy all files from the old server to the new server, taking precaution to
                preserve all file ownership and permissions as well as any POSIX ACLs that
                may have been created on the old server.
                </para></listitem>
        </itemizedlist>

        <para>
        When replacing a Samba domain controller (PDC or BDC) that uses LDAP, the new server
        need simply be configured to use the LDAP directory, and for the rest it should just
        work. The domain SID is obtained from the LDAP directory as part of the first connect
        to the LDAP directory server.
        </para>

        <para>
        All Samba servers, other than one that uses LDAP, depend on the tdb files, and
        particularly on the <filename>secrets.tdb</filename> file. So long as the tdb files are
        all in place, the &smb.conf; file is preserved, and either the hostname is identical
        or the <parameter>netbios name</parameter> is set to the original server name, Samba
        should correctly pick up the original SID and preserve all other settings. It is
        sound advice to validate this before turning the system over to users.
        </para>

        </sect3>

        </sect2>

        <sect2>
        <title>Migration of Samba Accounts to Active Directory</title>

        <para>
        Yes, it works. The Windows ADMT tool can be used to migrate Samba accounts
        to MS Active Directory.  There are a few pitfalls to be aware of:
        </para>

        <procedure>
        <title>Migration to Active Directory</title>

                <step><para>
                Administrator password must be THE SAME on the Samba server,
                the 2003 ADS, and the local Administrator account on the workstations. 
                Perhaps this goes without saying, but there needs to be an account
                called <constant>Administrator</constant> in your Samba domain, with 
                full administrative (root) rights to that domain.
                </para></step>

                <step><para>
                In the Advanced/DNS section of the TCP/IP settings on your Windows 
                workstations, make sure the <parameter>DNS suffix for this 
                connection</parameter> field is blank. 
                </para></step>

                <step><para>
                Because you are migrating from Samba, user passwords cannot be 
                migrated. You'll have to reset everyone's passwords. (If you were 
                migrating from NT4 to ADS, you could migrate passwords as well.)
                </para>

                <para>
                To date this has not been attempted with roaming profile support;
                it has been documented as working with local profiles.
                </para></step>

                <step><para>
                Disable the Windows Firewall on all workstations. Otherwise, 
                workstations won't be migrated to the new domain.
                </para></step>

                <step><para>
                <indexterm><primary>ADMT</primary></indexterm>
                When migrating machines, always test first (using ADMT's test mode) 
                and satisfy all errors before committing the migration. Note that the 
                test will always fail, because the machine will not have been actually 
                migrated. You'll need to interpret the errors to know whether the 
                failure was due to a problem or simply to the fact that it was just 
                a test.
                </para></step>

        </procedure>


        <para>
        <indexterm><primary>ADMT</primary></indexterm>
        There are some significant benefits of using the ADMT, besides just 
        migrating user accounts. ADMT can be found on the Windows 2003 CD.
        </para>

        <itemizedlist>
                <listitem><para>
                You can migrate workstations remotely. You can specify that SIDs 
                be simply added instead of replaced, giving you the option of joining a 
                workstation back to the old domain if something goes awry. The 
                workstations will be joined to the new domain.
                </para></listitem>

                <listitem><para>
                Not only are user accounts migrated from the old domain to the new 
                domain, but ACLs on the workstations are migrated as well. Like SIDs, 
                ACLs can be added instead of replaced.
                </para></listitem>

                <listitem><para>
                Locally stored user profiles on workstations are migrated as well, 
                presenting almost no disruption to the user. Saved passwords will be 
                lost, just as when you administratively reset the password in Windows ADS.
                </para></listitem>

                <listitem><para>
                The ADMT lets you test all operations before actually performing the 
                migration. Accounts and workstations can be migrated individually or in 
                batches. User accounts can be safely migrated all at once (since no 
                changes are made on the original domain). It is recommended to migrate only one 
                or two workstations as a test before committing them all.
                </para></listitem>

        </itemizedlist>

        </sect2>

</sect1>

</chapter>