[samba.git] / docs-xml / manpages / smbd.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="smbd.8">

<refmeta>
        <refentrytitle>smbd</refentrytitle>
        <manvolnum>8</manvolnum>
        <refmiscinfo class="source">Samba</refmiscinfo>
        <refmiscinfo class="manual">System Administration tools</refmiscinfo>
        <refmiscinfo class="version">&doc.version;</refmiscinfo>
</refmeta>


<refnamediv>
        <refname>smbd</refname>
        <refpurpose>server to provide SMB/CIFS services to clients</refpurpose>
</refnamediv>

<refsynopsisdiv>
        <cmdsynopsis>
                <command>smbd</command>
                <arg choice="opt">-D|--daemon</arg>
                <arg choice="opt">-i|--interactive</arg>
                <arg choice="opt">-F|--foreground</arg>
                <arg choice="opt">--no-process-group</arg>
                <arg choice="opt">-b|--build-options</arg>
                <arg choice="opt">-p &lt;port number(s)&gt;</arg>
                <arg choice="opt">-P &lt;profiling level&gt;</arg>
                <arg choice="opt">-d &lt;debug level&gt;</arg>
                <arg choice="opt">--debug-stdout</arg>
                <arg choice="opt">--configfile=&lt;configuration file&gt;</arg>
                <arg choice="opt">--option=&lt;name&gt;=&lt;value&gt;</arg>
                <arg choice="opt">-l|--log-basename &lt;log directory&gt;</arg>
                <arg choice="opt">--leak-report</arg>
                <arg choice="opt">--leak-report-full</arg>
                <arg choice="opt">-V|--version</arg>
        </cmdsynopsis>
</refsynopsisdiv>

<refsect1>
        <title>DESCRIPTION</title>
        <para>This program is part of the <citerefentry><refentrytitle>samba</refentrytitle>
        <manvolnum>7</manvolnum></citerefentry> suite.</para>

        <para><command>smbd</command> is the server daemon that 
        provides filesharing and printing services to Windows clients. 
        The server provides filespace and printer services to
        clients using the SMB (or CIFS) protocol. This is compatible 
        with the LanManager protocol, and can service LanManager 
        clients.  These include MSCLIENT 3.0 for DOS, Windows for 
        Workgroups, Windows 95/98/ME, Windows NT, Windows 2000, 
        OS/2, DAVE for Macintosh, and smbfs for Linux.</para>

        <para>An extensive description of the services that the 
        server can provide is given in the man page for the 
        configuration file controlling the attributes of those 
        services (see <citerefentry><refentrytitle>smb.conf</refentrytitle>
        <manvolnum>5</manvolnum></citerefentry>.  This man page will not describe the 
        services, but will concentrate on the administrative aspects 
        of running the server.</para>

        <para>Please note that there are significant security 
        implications to running this server, and the <citerefentry><refentrytitle>smb.conf</refentrytitle>
        <manvolnum>5</manvolnum></citerefentry> manual page should be regarded as mandatory reading before 
        proceeding with installation.</para>

        <para>A session is created whenever a client requests one. 
        Each client gets a copy of the server for each session. This 
        copy then services all connections made by the client during 
        that session. When all connections from its client are closed, 
        the copy of the server for that client terminates.</para>

        <para>The configuration file, and any files that it includes, 
        are automatically reloaded every three minutes, if they change.
        One can force a reload by sending a SIGHUP to the server. Reloading
        the configuration file will not affect connections to any service 
        that is already established.  Either the user will have to 
        disconnect from the service, or <command>smbd</command> killed and restarted.
        </para>

        <para>Instead of sending a SIGHUP signal, a request to reload configuration
        file may be sent using <citerefentry><refentrytitle>smbcontrol</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry> program.
        </para>

</refsect1>

<refsect1>
        <title>OPTIONS</title>

        <variablelist>
                <varlistentry>
                <term>-D|--daemon</term>
                <listitem><para>If specified, this parameter causes 
                the server to operate as a daemon. That is, it detaches 
                itself and runs in the background, fielding requests 
                on the appropriate port. Operating the server as a
                daemon is the recommended way of running <command>smbd</command> for 
                servers that provide more than casual use file and 
                print services.  This switch is assumed if <command>smbd
                </command> is executed on the command line of a shell.
                </para></listitem>
                </varlistentry>

                <varlistentry>
                <term>-i|--interactive</term>
                <listitem><para>If this parameter is specified it causes the
                server to run "interactively", not as a daemon, even if the
                server is executed on the command line of a shell. Setting this
                parameter negates the implicit daemon mode when run from the
                command line. <command>smbd</command> will only accept one
                connection and terminate. It will also log to standard output,
                as if the <command>-S</command> parameter had been given.
                </para></listitem>
                </varlistentry>

                <varlistentry>
                <term>-F|--foreground</term>
                <listitem><para>If specified, this parameter causes
                the main <command>smbd</command> process to not daemonize,
                i.e. double-fork and disassociate with the terminal.
                Child processes are still created as normal to service
                each connection request, but the main process does not
                exit. This operation mode is suitable for running
                <command>smbd</command> under process supervisors such
                as <command>supervise</command> and <command>svscan</command>
                from Daniel J. Bernstein's <command>daemontools</command>
                package, or the AIX process monitor.
                </para></listitem>
                </varlistentry>

                <varlistentry>
                <term>--no-process-group</term>
                <listitem><para>Do not create a new process group for smbd.
                </para></listitem>
                </varlistentry>

                <varlistentry>
                <term>-b|--build-options</term>
                <listitem><para>Prints information about how 
                Samba was built.</para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term>-p|--port&lt;port number(s)&gt;</term>
                <listitem><para><replaceable>port number(s)</replaceable> is a 
                space or comma-separated list of TCP ports smbd should listen on.
                The default value is taken from the <smbconfoption name="ports"/> parameter in &smb.conf;</para>

                <para>The default ports are 139 (used for SMB over NetBIOS over TCP)
                        and port 445 (used for plain SMB over TCP).
                </para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term>-P|--profiling-level&lt;profiling level&gt;</term>
                <listitem><para><replaceable>profiling level</replaceable> is a
                number specifying the level of profiling data to be collected.
                0 turns off profiling, 1 turns on counter profiling only,
                2 turns on complete profiling, and 3 resets all profiling data.
                </para></listitem>
                </varlistentry>

                &cmdline.common.samba.server;
                &popt.autohelp;

        </variablelist>
</refsect1>

<refsect1>
        <title>FILES</title>

        <variablelist>
                <varlistentry>
                <term><filename>/etc/inetd.conf</filename></term>
                <listitem><para>If the server is to be run by the 
                <command>inetd</command> meta-daemon, this file 
                must contain suitable startup information for the 
                meta-daemon. 
                </para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term><filename>/etc/rc</filename></term>
                <listitem><para>or whatever initialization script your 
                system uses).</para>

                <para>If running the server as a daemon at startup, 
                this file will need to contain an appropriate startup 
                sequence for the server. </para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term><filename>/etc/services</filename></term>
                <listitem><para>If running the server via the 
                meta-daemon <command>inetd</command>, this file 
                must contain a mapping of service name (e.g., netbios-ssn) 
                to service port (e.g., 139) and protocol type (e.g., tcp). 
                </para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term><filename>/usr/local/samba/lib/smb.conf</filename></term>
                <listitem><para>This is the default location of the <citerefentry><refentrytitle>smb.conf</refentrytitle>
                <manvolnum>5</manvolnum></citerefentry> server configuration file. Other common places that systems 
                install this file are <filename>/usr/samba/lib/smb.conf</filename> 
                and <filename>/etc/samba/smb.conf</filename>.</para>
                
                <para>This file describes all the services the server 
                is to make available to clients. See <citerefentry><refentrytitle>smb.conf</refentrytitle>
                <manvolnum>5</manvolnum></citerefentry> for more information.</para>
                </listitem>
                </varlistentry>
        </variablelist>
</refsect1>

<refsect1>
        <title>LIMITATIONS</title>
        <para>On some systems <command>smbd</command> cannot change uid back 
        to root after a setuid() call.  Such systems are called 
        trapdoor uid systems. If you have such a system, 
        you will be unable to connect from a client (such as a PC) as 
        two different users at once. Attempts to connect the
        second user will result in access denied or 
        similar.</para>
</refsect1>

<refsect1>
        <title>ENVIRONMENT VARIABLES</title>

        <variablelist>
                <varlistentry>
                <term><envar>PRINTER</envar></term>
                <listitem><para>If no printer name is specified to 
                printable services, most systems will use the value of 
                this variable (or <constant>lp</constant> if this variable is 
                not defined) as the name of the printer to use. This 
                is not specific to the server, however.</para></listitem>
                </varlistentry>
        </variablelist>
</refsect1>


<refsect1>
        <title>PAM INTERACTION</title>
        <para>Samba uses PAM for authentication (when presented with a plaintext 
        password), for account checking (is this account disabled?) and for
        session management.  The degree too which samba supports PAM is restricted
        by the limitations of the SMB protocol and the <smbconfoption name="obey pam restrictions"/> <citerefentry><refentrytitle>smb.conf</refentrytitle>
        <manvolnum>5</manvolnum></citerefentry> parameter.  When this is set, the following restrictions apply:
        </para>

        <itemizedlist>
        <listitem><para><emphasis>Account Validation</emphasis>:  All accesses to a 
        samba server are checked 
        against PAM to see if the account is valid, not disabled and is permitted to
        login at this time.  This also applies to encrypted logins.
        </para></listitem>

        <listitem><para><emphasis>Session Management</emphasis>:  When not using share 
        level security, users must pass PAM's session checks before access
        is granted.  Note however, that this is bypassed in share level security.
        Note also that some older pam configuration files may need a line 
        added for session support. 
        </para></listitem>
        </itemizedlist>
</refsect1>

<refsect1>
        <title>VERSION</title>

        <para>This man page is part of version &doc.version; of
        the Samba suite.</para>
</refsect1>

<refsect1>
        <title>DIAGNOSTICS</title>

        <para>Most diagnostics issued by the server are logged 
        in a specified log file. The log file name is specified 
        at compile time, but may be overridden on the command line.</para>

        <para>The number and nature of diagnostics available depends 
        on the debug level used by the server. If you have problems, set 
        the debug level to 3 and peruse the log files.</para>

        <para>Most messages are reasonably self-explanatory. Unfortunately, 
        at the time this man page was created, there are too many diagnostics 
        available in the source code to warrant describing each and every 
        diagnostic. At this stage your best bet is still to grep the 
        source code and inspect the conditions that gave rise to the 
        diagnostics you are seeing.</para>
</refsect1>

<refsect1>
        <title>TDB FILES</title>

        <para>Samba stores it's data in several TDB (Trivial Database) files, usually located in <filename>/var/lib/samba</filename>.</para>
        
        <para>
        (*) information persistent across restarts (but not
        necessarily important to backup).
        </para>

<variablelist>
<varlistentry><term>account_policy.tdb*</term>
<listitem>
<para>NT account policy settings such as pw expiration, etc...</para>
</listitem>
</varlistentry>

<varlistentry><term>brlock.tdb</term>
<listitem><para>byte range locks</para></listitem>
</varlistentry>

<varlistentry><term>browse.dat</term>
<listitem><para>browse lists</para></listitem>
</varlistentry>

<varlistentry><term>gencache.tdb</term>
<listitem><para>generic caching db</para></listitem>
</varlistentry>

<varlistentry><term>group_mapping.tdb*</term>
<listitem><para>group mapping information</para></listitem>
</varlistentry>

<varlistentry><term>locking.tdb</term>
<listitem><para>share modes &amp; oplocks</para></listitem>
</varlistentry>

<varlistentry><term>login_cache.tdb*</term>
<listitem><para>bad pw attempts</para></listitem>
</varlistentry>

<varlistentry><term>messages.tdb</term>
<listitem><para>Samba messaging system</para></listitem>
</varlistentry>

<varlistentry><term>netsamlogon_cache.tdb*</term>
<listitem><para>cache of user net_info_3 struct from net_samlogon() request (as a domain member)</para></listitem>
</varlistentry>

<varlistentry><term>ntdrivers.tdb*</term>
<listitem><para>installed printer drivers</para></listitem>
</varlistentry>

<varlistentry><term>ntforms.tdb*</term>
<listitem><para>installed printer forms</para></listitem>
</varlistentry>

<varlistentry><term>ntprinters.tdb*</term>
<listitem><para>installed printer information</para></listitem>
</varlistentry>

<varlistentry><term>printing/</term>
<listitem><para>directory containing tdb per print queue of cached lpq output</para></listitem>
</varlistentry>

<varlistentry><term>registry.tdb</term>
<listitem><para>Windows registry skeleton (connect via regedit.exe)</para></listitem>
</varlistentry>

<varlistentry><term>smbXsrv_session_global.tdb</term>
<listitem><para>session information (e.g. support for 'utmp = yes')</para></listitem>
</varlistentry>

<varlistentry><term>smbXsrv_tcon_global.tdb</term>
<listitem><para>share connections (used to enforce max connections, etc...)</para></listitem>
</varlistentry>

<varlistentry><term>smbXsrv_open_global.tdb</term>
<listitem><para>open file handles (used durable handles, etc...)</para></listitem>
</varlistentry>

<varlistentry><term>share_info.tdb*</term>
<listitem><para>share acls</para></listitem>
</varlistentry>

<varlistentry><term>winbindd_cache.tdb</term>
<listitem><para>winbindd's cache of user lists, etc...</para></listitem>
</varlistentry>

<varlistentry><term>winbindd_idmap.tdb*</term>
<listitem><para>winbindd's local idmap db</para></listitem>
</varlistentry>

<varlistentry><term>wins.dat*</term>
<listitem><para>wins database when 'wins support = yes'</para></listitem>
</varlistentry>

</variablelist>

</refsect1>

<refsect1>
        <title>SIGNALS</title>

        <para>Sending the <command>smbd</command> a SIGHUP will cause it to 
        reload its <filename>smb.conf</filename> configuration 
        file within a short period of time.</para>

        <para>To shut down a user's <command>smbd</command> process it is recommended 
        that <command>SIGKILL (-9)</command> <emphasis>NOT</emphasis> 
        be used, except as a last resort, as this may leave the shared
        memory area in an inconsistent state. The safe way to terminate 
        an <command>smbd</command> is to send it a SIGTERM (-15) signal and wait for 
        it to die on its own.</para>

        <para>The debug log level of <command>smbd</command> may be raised
        or lowered using <citerefentry><refentrytitle>smbcontrol</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry> program (SIGUSR[1|2] signals are no longer 
        used since Samba 2.2). This is to allow transient problems to be diagnosed, 
        whilst still running at a normally low log level.</para>

        <para>Note that as the signal handlers send a debug write, 
        they are not re-entrant in <command>smbd</command>. This you should wait until 
        <command>smbd</command> is in a state of waiting for an incoming SMB before 
        issuing them. It is possible to make the signal handlers safe 
        by un-blocking the signals before the select call and re-blocking 
        them after, however this would affect performance.</para>
</refsect1>

<refsect1>
        <title>SEE ALSO</title>
        <para><citerefentry><refentrytitle>hosts_access</refentrytitle>
        <manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>inetd</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>nmbd</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>smb.conf</refentrytitle>
        <manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>smbclient</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>testparm</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry>, and the 
        Internet RFC's  <filename>rfc1001.txt</filename>, <filename>rfc1002.txt</filename>. 
        In addition the CIFS (formerly SMB) specification is available 
        as a link from the Web page <ulink noescape="1" url="https://www.samba.org/cifs/">
        https://www.samba.org/cifs/</ulink>.</para>
</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>