1 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN">
5 <refentrytitle>smbd</refentrytitle>
6 <manvolnum>8</manvolnum>
11 <refname>smbd</refname>
12 <refpurpose>server to provide SMB/CIFS services to clients</refpurpose>
17 <command>smbd</command>
18 <arg choice="opt">-D</arg>
19 <arg choice="opt">-i</arg>
20 <arg choice="opt">-h</arg>
21 <arg choice="opt">-V</arg>
22 <arg choice="opt">-b</arg>
23 <arg choice="opt">-d <debug level></arg>
24 <arg choice="opt">-l <log directory></arg>
25 <arg choice="opt">-p <port number></arg>
26 <arg choice="opt">-O <socket option></arg>
27 <arg choice="opt">-s <configuration file></arg>
32 <title>DESCRIPTION</title>
33 <para>This program is part of the Samba suite.</para>
35 <para><command>smbd</command> is the server daemon that
36 provides filesharing and printing services to Windows clients.
37 The server provides filespace and printer services to
38 clients using the SMB (or CIFS) protocol. This is compatible
39 with the LanManager protocol, and can service LanManager
40 clients. These include MSCLIENT 3.0 for DOS, Windows for
41 Workgroups, Windows 95/98/ME, Windows NT, Windows 2000,
42 OS/2, DAVE for Macintosh, and smbfs for Linux.</para>
44 <para>An extensive description of the services that the
45 server can provide is given in the man page for the
46 configuration file controlling the attributes of those
47 services (see <ulink url="smb.conf.5.html"><filename>smb.conf(5)
48 </filename></ulink>. This man page will not describe the
49 services, but will concentrate on the administrative aspects
50 of running the server.</para>
52 <para>Please note that there are significant security
53 implications to running this server, and the <ulink
54 url="smb.conf.5.html"><filename>smb.conf(5)</filename></ulink>
55 manpage should be regarded as mandatory reading before
56 proceeding with installation.</para>
58 <para>A session is created whenever a client requests one.
59 Each client gets a copy of the server for each session. This
60 copy then services all connections made by the client during
61 that session. When all connections from its client are closed,
62 the copy of the server for that client terminates.</para>
64 <para>The configuration file, and any files that it includes,
65 are automatically reloaded every minute, if they change. You
66 can force a reload by sending a SIGHUP to the server. Reloading
67 the configuration file will not affect connections to any service
68 that is already established. Either the user will have to
69 disconnect from the service, or <command>smbd</command> killed and restarted.</para>
73 <title>OPTIONS</title>
78 <listitem><para>If specified, this parameter causes
79 the server to operate as a daemon. That is, it detaches
80 itself and runs in the background, fielding requests
81 on the appropriate port. Operating the server as a
82 daemon is the recommended way of running <command>smbd</command> for
83 servers that provide more than casual use file and
84 print services. This switch is assumed if <command>smbd
85 </command> is executed on the command line of a shell.
91 <listitem><para>If this parameter is specified it causes the
92 server to run "interactively", not as a daemon, even if the
93 server is executed on the command line of a shell. Setting this
94 parameter negates the implicit deamon mode when run from the
101 <listitem><para>Prints the help information (usage)
102 for <command>smbd</command>.</para></listitem>
107 <listitem><para>Prints the version number for
108 <command>smbd</command>.</para></listitem>
113 <listitem><para>Prints information about how
114 Samba was built.</para></listitem>
118 <term>-d <debug level></term>
119 <listitem><para><replaceable>debuglevel</replaceable> is an integer
120 from 0 to 10. The default value if this parameter is
121 not specified is zero.</para>
123 <para>The higher this value, the more detail will be
124 logged to the log files about the activities of the
125 server. At level 0, only critical errors and serious
126 warnings will be logged. Level 1 is a reasonable level for
127 day to day running - it generates a small amount of
128 information about operations carried out.</para>
130 <para>Levels above 1 will generate considerable
131 amounts of log data, and should only be used when
132 investigating a problem. Levels above 3 are designed for
133 use only by developers and generate HUGE amounts of log
134 data, most of which is extremely cryptic.</para>
136 <para>Note that specifying this parameter here will
137 override the <ulink url="smb.conf.5.html#loglevel">log
138 level</ulink> parameter in the <ulink url="smb.conf.5.html">
139 <filename>smb.conf(5)</filename></ulink> file.</para>
144 <term>-l <log directory></term>
145 <listitem><para>If specified,
146 <replaceable>log directory</replaceable>
147 specifies a log directory into which the "log.smbd" log
148 file will be created for informational and debug
149 messages from the running server. The log
150 file generated is never removed by the server although
151 its size may be controlled by the <ulink
152 url="smb.conf.5.html#maxlogsize">max log size</ulink>
153 option in the <ulink url="smb.conf.5.html"><filename>
154 smb.conf(5)</filename></ulink> file. <emphasis>Beware:</emphasis>
155 If the directory specified does not exist, <command>smbd</command>
156 will log to the default debug log location defined at compile time.
159 <para>The default log directory is specified at
160 compile time.</para></listitem>
164 <term>-O <socket options></term>
165 <listitem><para>See the <ulink
166 url="smb.conf.5.html#socketoptions">socket options</ulink>
167 parameter in the <ulink url="smb.conf.5.html"><filename>smb.conf(5)
168 </filename></ulink> file for details.</para></listitem>
172 <term>-p <port number></term>
173 <listitem><para><replaceable>port number</replaceable> is a positive integer
174 value. The default value if this parameter is not
175 specified is 139.</para>
177 <para>This number is the port number that will be
178 used when making connections to the server from client
179 software. The standard (well-known) port number for the
180 SMB over TCP is 139, hence the default. If you wish to
181 run the server as an ordinary user rather than
182 as root, most systems will require you to use a port
183 number greater than 1024 - ask your system administrator
184 for help if you are in this situation.</para>
186 <para>In order for the server to be useful by most
187 clients, should you configure it on a port other
188 than 139, you will require port redirection services
189 on port 139, details of which are outlined in rfc1002.txt
190 section 4.3.5.</para>
192 <para>This parameter is not normally specified except
193 in the above situation.</para></listitem>
197 <term>-s <configuration file></term>
198 <listitem><para>The file specified contains the
199 configuration details required by the server. The
200 information in this file includes server-specific
201 information such as what printcap file to use, as well
202 as descriptions of all the services that the server is
203 to provide. See <ulink url="smb.conf.5.html"><filename>
204 smb.conf(5)</filename></ulink> for more information.
205 The default configuration file name is determined at
206 compile time.</para></listitem>
216 <term><filename>/etc/inetd.conf</filename></term>
217 <listitem><para>If the server is to be run by the
218 <command>inetd</command> meta-daemon, this file
219 must contain suitable startup information for the
220 meta-daemon. See the <ulink url="UNIX_INSTALL.html">UNIX_INSTALL.html</ulink>
221 document for details.
226 <term><filename>/etc/rc</filename></term>
227 <listitem><para>or whatever initialization script your
230 <para>If running the server as a daemon at startup,
231 this file will need to contain an appropriate startup
232 sequence for the server. See the <ulink url="UNIX_INSTALL.html">UNIX_INSTALL.html</ulink>
233 document for details.</para></listitem>
237 <term><filename>/etc/services</filename></term>
238 <listitem><para>If running the server via the
239 meta-daemon <command>inetd</command>, this file
240 must contain a mapping of service name (e.g., netbios-ssn)
241 to service port (e.g., 139) and protocol type (e.g., tcp).
242 See the <ulink url="UNIX_INSTALL.html">UNIX_INSTALL.html</ulink>
243 document for details.</para></listitem>
247 <term><filename>/usr/local/samba/lib/smb.conf</filename></term>
248 <listitem><para>This is the default location of the
249 <ulink url="smb.conf.5.html"><filename>smb.conf</filename></ulink>
250 server configuration file. Other common places that systems
251 install this file are <filename>/usr/samba/lib/smb.conf</filename>
252 and <filename>/etc/smb.conf</filename>.</para>
254 <para>This file describes all the services the server
255 is to make available to clients. See <ulink url="smb.conf.5.html">
256 <filename>smb.conf(5)</filename></ulink> for more information.</para>
263 <title>LIMITATIONS</title>
264 <para>On some systems <command>smbd</command> cannot change uid back
265 to root after a setuid() call. Such systems are called
266 trapdoor uid systems. If you have such a system,
267 you will be unable to connect from a client (such as a PC) as
268 two different users at once. Attempts to connect the
269 second user will result in access denied or
274 <title>ENVIRONMENT VARIABLES</title>
278 <term><envar>PRINTER</envar></term>
279 <listitem><para>If no printer name is specified to
280 printable services, most systems will use the value of
281 this variable (or <constant>lp</constant> if this variable is
282 not defined) as the name of the printer to use. This
283 is not specific to the server, however.</para></listitem>
290 <title>PAM INTERACTION</title>
291 <para>Samba uses PAM for authentication (when presented with a plaintext
292 password), for account checking (is this account disabled?) and for
293 session management. The degree too which samba supports PAM is restricted
294 by the limitations of the SMB protocol and the
295 <ulink url="smb.conf.5.html#OBEYPAMRESRICTIONS">obey pam restricions</ulink>
296 smb.conf paramater. When this is set, the following restrictions apply:
300 <listitem><para><emphasis>Account Validation</emphasis>: All accesses to a
301 samba server are checked
302 against PAM to see if the account is vaild, not disabled and is permitted to
303 login at this time. This also applies to encrypted logins.
306 <listitem><para><emphasis>Session Management</emphasis>: When not using share
307 level secuirty, users must pass PAM's session checks before access
308 is granted. Note however, that this is bypassed in share level secuirty.
309 Note also that some older pam configuration files may need a line
310 added for session support.
316 <title>VERSION</title>
318 <para>This man page is correct for version 3.0 of
319 the Samba suite.</para>
323 <title>DIAGNOSTICS</title>
325 <para>Most diagnostics issued by the server are logged
326 in a specified log file. The log file name is specified
327 at compile time, but may be overridden on the command line.</para>
329 <para>The number and nature of diagnostics available depends
330 on the debug level used by the server. If you have problems, set
331 the debug level to 3 and peruse the log files.</para>
333 <para>Most messages are reasonably self-explanatory. Unfortunately,
334 at the time this man page was created, there are too many diagnostics
335 available in the source code to warrant describing each and every
336 diagnostic. At this stage your best bet is still to grep the
337 source code and inspect the conditions that gave rise to the
338 diagnostics you are seeing.</para>
342 <title>SIGNALS</title>
344 <para>Sending the <command>smbd</command> a SIGHUP will cause it to
345 reload its <filename>smb.conf</filename> configuration
346 file within a short period of time.</para>
348 <para>To shut down a user's <command>smbd</command> process it is recommended
349 that <command>SIGKILL (-9)</command> <emphasis>NOT</emphasis>
350 be used, except as a last resort, as this may leave the shared
351 memory area in an inconsistent state. The safe way to terminate
352 an <command>smbd</command> is to send it a SIGTERM (-15) signal and wait for
353 it to die on its own.</para>
355 <para>The debug log level of <command>smbd</command> may be raised
356 or lowered using <ulink url="smbcontrol.1.html"><command>smbcontrol(1)
357 </command></ulink> program (SIGUSR[1|2] signals are no longer used in
358 Samba 2.2). This is to allow transient problems to be diagnosed,
359 whilst still running at a normally low log level.</para>
361 <para>Note that as the signal handlers send a debug write,
362 they are not re-entrant in <command>smbd</command>. This you should wait until
363 <command>smbd</command> is in a state of waiting for an incoming SMB before
364 issuing them. It is possible to make the signal handlers safe
365 by un-blocking the signals before the select call and re-blocking
366 them after, however this would affect performance.</para>
370 <title>SEE ALSO</title>
371 <para>hosts_access(5), <command>inetd(8)</command>,
372 <ulink url="nmbd.8.html"><command>nmbd(8)</command></ulink>,
373 <ulink url="smb.conf.5.html"><filename>smb.conf(5)</filename>
374 </ulink>, <ulink url="smbclient.1.html"><command>smbclient(1)
375 </command></ulink>, <ulink url="testparm.1.html"><command>
376 testparm(1)</command></ulink>, <ulink url="testprns.1.html">
377 <command>testprns(1)</command></ulink>, and the Internet RFC's
378 <filename>rfc1001.txt</filename>, <filename>rfc1002.txt</filename>.
379 In addition the CIFS (formerly SMB) specification is available
380 as a link from the Web page <ulink url="http://samba.org/cifs/">
381 http://samba.org/cifs/</ulink>.</para>
385 <title>AUTHOR</title>
387 <para>The original Samba software and related utilities
388 were created by Andrew Tridgell. Samba is now developed
389 by the Samba Team as an Open Source project similar
390 to the way the Linux kernel is developed.</para>
392 <para>The original Samba man pages were written by Karl Auer.
393 The man page sources were converted to YODL format (another
394 excellent piece of Open Source software, available at
395 <ulink url="ftp://ftp.icce.rug.nl/pub/unix/">
396 ftp://ftp.icce.rug.nl/pub/unix/</ulink>) and updated for the Samba 2.0
397 release by Jeremy Allison. The conversion to DocBook for
398 Samba 2.2 was done by Gerald Carter</para>