path: root/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">4.0</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</arg>
		<arg choice="opt">-F</arg>
		<arg choice="opt">-S</arg>
		<arg choice="opt">-i</arg>
		<arg choice="opt">-h</arg>
		<arg choice="opt">-V</arg>
		<arg choice="opt">-b</arg>
		<arg choice="opt">-d &lt;debug level&gt;</arg>
		<arg choice="opt">-l &lt;log directory&gt;</arg>
		<arg choice="opt">-p &lt;port number(s)&gt;</arg>
		<arg choice="opt">-P &lt;profiling level&gt;</arg>
		<arg choice="opt">-O &lt;socket option&gt;</arg>
		<arg choice="opt">-s &lt;configuration file&gt;</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 minute, if they change.  You 
	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>
</refsect1>

<refsect1>
	<title>OPTIONS</title>

	<variablelist>
		<varlistentry>
		<term>-D</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>-F</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>-S</term>
		<listitem><para>If specified, this parameter causes
		<command>smbd</command> to log to standard output rather
		than a file.</para></listitem>
		</varlistentry>

		<varlistentry>
		<term>-i</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> also logs to standard
		output, as if the <command>-S</command> parameter had been
		given.
		</para></listitem>
		</varlistentry>
		
		&stdarg.server.debug;
		&popt.common.samba;
		&stdarg.help;

		<varlistentry>
		<term>-b</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>
	</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 correct for version 3 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>connections.tdb</term>
<listitem><para>share connections (used to enforce max connections, etc...)</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>sessionid.tdb</term>
<listitem><para>session information (e.g. support for 'utmp = yes')</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>, <citerefentry><refentrytitle>testprns</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="http://samba.org/cifs/"> 
	http://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>
	
	<para>The original Samba man pages were written by Karl Auer. 
	The man page sources were converted to YODL format (another 
	excellent piece of Open Source software, available at <ulink url="ftp://ftp.icce.rug.nl/pub/unix/">
	ftp://ftp.icce.rug.nl/pub/unix/</ulink>) and updated for the Samba 2.0 
	release by Jeremy Allison.  The conversion to DocBook for 
	Samba 2.2 was done by Gerald Carter. The conversion to DocBook XML 4.2 for
	Samba 3.0 was done by Alexander Bokovoy.</para>
</refsect1>

</refentry>