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">-a</arg>
20 <arg choice="opt">-i</arg>
21 <arg choice="opt">-o</arg>
22 <arg choice="opt">-P</arg>
23 <arg choice="opt">-h</arg>
24 <arg choice="opt">-V</arg>
25 <arg choice="opt">-b</arg>
26 <arg choice="opt">-d <debug level></arg>
27 <arg choice="opt">-l <log directory></arg>
28 <arg choice="opt">-p <port number></arg>
29 <arg choice="opt">-O <socket option></arg>
30 <arg choice="opt">-s <configuration file></arg>
35 <title>DESCRIPTION</title>
36 <para>This program is part of the Samba suite.</para>
38 <para><command>smbd</command> is the server daemon that
39 provides filesharing and printing services to Windows clients.
40 The server provides filespace and printer services to
41 clients using the SMB (or CIFS) protocol. This is compatible
42 with the LanManager protocol, and can service LanManager
43 clients. These include MSCLIENT 3.0 for DOS, Windows for
44 Workgroups, Windows 95/98/ME, Windows NT, Windows 2000,
45 OS/2, DAVE for Macintosh, and smbfs for Linux.</para>
47 <para>An extensive description of the services that the
48 server can provide is given in the man page for the
49 configuration file controlling the attributes of those
50 services (see <ulink url="smb.conf.5.html"><filename>smb.conf(5)
51 </filename></ulink>. This man page will not describe the
52 services, but will concentrate on the administrative aspects
53 of running the server.</para>
55 <para>Please note that there are significant security
56 implications to running this server, and the <ulink
57 url="smb.conf.5.html"><filename>smb.conf(5)</filename></ulink>
58 manpage should be regarded as mandatory reading before
59 proceeding with installation.</para>
61 <para>A session is created whenever a client requests one.
62 Each client gets a copy of the server for each session. This
63 copy then services all connections made by the client during
64 that session. When all connections from its client are closed,
65 the copy of the server for that client terminates.</para>
67 <para>The configuration file, and any files that it includes,
68 are automatically reloaded every minute, if they change. You
69 can force a reload by sending a SIGHUP to the server. Reloading
70 the configuration file will not affect connections to any service
71 that is already established. Either the user will have to
72 disconnect from the service, or <command>smbd</command> killed and restarted.</para>
76 <title>OPTIONS</title>
81 <listitem><para>If specified, this parameter causes
82 the server to operate as a daemon. That is, it detaches
83 itself and runs in the background, fielding requests
84 on the appropriate port. Operating the server as a
85 daemon is the recommended way of running <command>smbd</command> for
86 servers that provide more than casual use file and
87 print services. This switch is assumed if <command>smbd
88 </command> is executed on the command line of a shell.
94 <listitem><para>If this parameter is specified, each new
95 connection will append log messages to the log file.
96 This is the default.</para></listitem>
101 <listitem><para>If this parameter is specified it causes the
102 server to run "interactively", not as a daemon, even if the
103 server is executed on the command line of a shell. Setting this
104 parameter negates the implicit deamon mode when run from the
111 <listitem><para>If this parameter is specified, the
112 log files will be overwritten when opened. By default,
113 <command>smbd</command> will append entries to the log
114 files.</para></listitem>
119 <listitem><para>Passive option. Causes <command>smbd</command> not to
120 send any network traffic out. Used for debugging by
121 the developers only.</para></listitem>
126 <listitem><para>Prints the help information (usage)
127 for <command>smbd</command>.</para></listitem>
132 <listitem><para>Prints the version number for
133 <command>smbd</command>.</para></listitem>
138 <listitem><para>Prints information about how
139 Samba was built.</para></listitem>
143 <term>-d <debug level></term>
144 <listitem><para><replaceable>debuglevel</replaceable> is an integer
145 from 0 to 10. The default value if this parameter is
146 not specified is zero.</para>
148 <para>The higher this value, the more detail will be
149 logged to the log files about the activities of the
150 server. At level 0, only critical errors and serious
151 warnings will be logged. Level 1 is a reasonable level for
152 day to day running - it generates a small amount of
153 information about operations carried out.</para>
155 <para>Levels above 1 will generate considerable
156 amounts of log data, and should only be used when
157 investigating a problem. Levels above 3 are designed for
158 use only by developers and generate HUGE amounts of log
159 data, most of which is extremely cryptic.</para>
161 <para>Note that specifying this parameter here will
162 override the <ulink url="smb.conf.5.html#loglevel">log
163 level</ulink> parameter in the <ulink url="smb.conf.5.html">
164 <filename>smb.conf(5)</filename></ulink> file.</para>
169 <term>-l <log directory></term>
170 <listitem><para>If specified,
171 <replaceable>log directory</replaceable>
172 specifies a log directory into which the "log.smbd" log
173 file will be created for informational and debug
174 messages from the running server. The log
175 file generated is never removed by the server although
176 its size may be controlled by the <ulink
177 url="smb.conf.5.html#maxlogsize">max log size</ulink>
178 option in the <ulink url="smb.conf.5.html"><filename>
179 smb.conf(5)</filename></ulink> file.
182 <para>The default log directory is specified at
183 compile time.</para></listitem>
187 <term>-O <socket options></term>
188 <listitem><para>See the <ulink
189 url="smb.conf.5.html#socketoptions">socket options</ulink>
190 parameter in the <ulink url="smb.conf.5.html"><filename>smb.conf(5)
191 </filename></ulink> file for details.</para></listitem>
195 <term>-p <port number></term>
196 <listitem><para><replaceable>port number</replaceable> is a positive integer
197 value. The default value if this parameter is not
198 specified is 139.</para>
200 <para>This number is the port number that will be
201 used when making connections to the server from client
202 software. The standard (well-known) port number for the
203 SMB over TCP is 139, hence the default. If you wish to
204 run the server as an ordinary user rather than
205 as root, most systems will require you to use a port
206 number greater than 1024 - ask your system administrator
207 for help if you are in this situation.</para>
209 <para>In order for the server to be useful by most
210 clients, should you configure it on a port other
211 than 139, you will require port redirection services
212 on port 139, details of which are outlined in rfc1002.txt
213 section 4.3.5.</para>
215 <para>This parameter is not normally specified except
216 in the above situation.</para></listitem>
220 <term>-s <configuration file></term>
221 <listitem><para>The file specified contains the
222 configuration details required by the server. The
223 information in this file includes server-specific
224 information such as what printcap file to use, as well
225 as descriptions of all the services that the server is
226 to provide. See <ulink url="smb.conf.5.html"><filename>
227 smb.conf(5)</filename></ulink> for more information.
228 The default configuration file name is determined at
229 compile time.</para></listitem>
239 <term><filename>/etc/inetd.conf</filename></term>
240 <listitem><para>If the server is to be run by the
241 <command>inetd</command> meta-daemon, this file
242 must contain suitable startup information for the
243 meta-daemon. See the <ulink url="UNIX_INSTALL.html">UNIX_INSTALL.html</ulink>
244 document for details.
249 <term><filename>/etc/rc</filename></term>
250 <listitem><para>or whatever initialization script your
253 <para>If running the server as a daemon at startup,
254 this file will need to contain an appropriate startup
255 sequence for the server. See the <ulink url="UNIX_INSTALL.html">UNIX_INSTALL.html</ulink>
256 document for details.</para></listitem>
260 <term><filename>/etc/services</filename></term>
261 <listitem><para>If running the server via the
262 meta-daemon <command>inetd</command>, this file
263 must contain a mapping of service name (e.g., netbios-ssn)
264 to service port (e.g., 139) and protocol type (e.g., tcp).
265 See the <ulink url="UNIX_INSTALL.html">UNIX_INSTALL.html</ulink>
266 document for details.</para></listitem>
270 <term><filename>/usr/local/samba/lib/smb.conf</filename></term>
271 <listitem><para>This is the default location of the
272 <ulink url="smb.conf.5.html"><filename>smb.conf</filename></ulink>
273 server configuration file. Other common places that systems
274 install this file are <filename>/usr/samba/lib/smb.conf</filename>
275 and <filename>/etc/smb.conf</filename>.</para>
277 <para>This file describes all the services the server
278 is to make available to clients. See <ulink url="smb.conf.5.html">
279 <filename>smb.conf(5)</filename></ulink> for more information.</para>
286 <title>LIMITATIONS</title>
287 <para>On some systems <command>smbd</command> cannot change uid back
288 to root after a setuid() call. Such systems are called
289 trapdoor uid systems. If you have such a system,
290 you will be unable to connect from a client (such as a PC) as
291 two different users at once. Attempts to connect the
292 second user will result in access denied or
297 <title>ENVIRONMENT VARIABLES</title>
301 <term><envar>PRINTER</envar></term>
302 <listitem><para>If no printer name is specified to
303 printable services, most systems will use the value of
304 this variable (or <constant>lp</constant> if this variable is
305 not defined) as the name of the printer to use. This
306 is not specific to the server, however.</para></listitem>
313 <title>PAM INTERACTION</title>
314 <para>Samba uses PAM for authentication (when presented with a plaintext
315 password), for account checking (is this account disabled?) and for
316 session management. The degree too which samba supports PAM is restricted
317 by the limitations of the SMB protocol and the
318 <ulink url="smb.conf.5.html#OBEYPAMRESRICTIONS">obey pam restricions</ulink>
319 smb.conf paramater. When this is set, the following restrictions apply:
323 <listitem><para><emphasis>Account Validation</emphasis>: All acccesses to a
324 samba server are checked
325 against PAM to see if the account is vaild, not disabled and is permitted to
326 login at this time. This also applies to encrypted logins.
329 <listitem><para><emphasis>Session Management</emphasis>: When not using share
330 level secuirty, users must pass PAM's session checks before access
331 is granted. Note however, that this is bypassed in share level secuirty.
332 Note also that some older pam configuration files may need a line
333 added for session support.
339 <title>VERSION</title>
341 <para>This man page is correct for version 2.2 of
342 the Samba suite.</para>
346 <title>DIAGNOSTICS</title>
348 <para>Most diagnostics issued by the server are logged
349 in a specified log file. The log file name is specified
350 at compile time, but may be overridden on the command line.</para>
352 <para>The number and nature of diagnostics available depends
353 on the debug level used by the server. If you have problems, set
354 the debug level to 3 and peruse the log files.</para>
356 <para>Most messages are reasonably self-explanatory. Unfortunately,
357 at the time this man page was created, there are too many diagnostics
358 available in the source code to warrant describing each and every
359 diagnostic. At this stage your best bet is still to grep the
360 source code and inspect the conditions that gave rise to the
361 diagnostics you are seeing.</para>
365 <title>SIGNALS</title>
367 <para>Sending the <command>smbd</command> a SIGHUP will cause it to
368 reload its <filename>smb.conf</filename> configuration
369 file within a short period of time.</para>
371 <para>To shut down a user's <command>smbd</command> process it is recommended
372 that <command>SIGKILL (-9)</command> <emphasis>NOT</emphasis>
373 be used, except as a last resort, as this may leave the shared
374 memory area in an inconsistent state. The safe way to terminate
375 an <command>smbd</command> is to send it a SIGTERM (-15) signal and wait for
376 it to die on its own.</para>
378 <para>The debug log level of <command>smbd</command> may be raised
379 or lowered using <ulink url="smbcontrol.1.html"><command>smbcontrol(1)
380 </command></ulink> program (SIGUSR[1|2] signals are no longer used in
381 Samba 2.2). This is to allow transient problems to be diagnosed,
382 whilst still running at a normally low log level.</para>
384 <para>Note that as the signal handlers send a debug write,
385 they are not re-entrant in <command>smbd</command>. This you should wait until
386 <command>smbd</command> is in a state of waiting for an incoming SMB before
387 issuing them. It is possible to make the signal handlers safe
388 by un-blocking the signals before the select call and re-blocking
389 them after, however this would affect performance.</para>
393 <title>SEE ALSO</title>
394 <para>hosts_access(5), <command>inetd(8)</command>,
395 <ulink url="nmbd.8.html"><command>nmbd(8)</command></ulink>,
396 <ulink url="smb.conf.5.html"><filename>smb.conf(5)</filename>
397 </ulink>, <ulink url="smbclient.1.html"><command>smbclient(1)
398 </command></ulink>, <ulink url="testparm.1.html"><command>
399 testparm(1)</command></ulink>, <ulink url="testprns.1.html">
400 <command>testprns(1)</command></ulink>, and the Internet RFC's
401 <filename>rfc1001.txt</filename>, <filename>rfc1002.txt</filename>.
402 In addition the CIFS (formerly SMB) specification is available
403 as a link from the Web page <ulink url="http://samba.org/cifs/">
404 http://samba.org/cifs/</ulink>.</para>
408 <title>AUTHOR</title>
410 <para>The original Samba software and related utilities
411 were created by Andrew Tridgell. Samba is now developed
412 by the Samba Team as an Open Source project similar
413 to the way the Linux kernel is developed.</para>
415 <para>The original Samba man pages were written by Karl Auer.
416 The man page sources were converted to YODL format (another
417 excellent piece of Open Source software, available at
418 <ulink url="ftp://ftp.icce.rug.nl/pub/unix/">
419 ftp://ftp.icce.rug.nl/pub/unix/</ulink>) and updated for the Samba 2.0
420 release by Jeremy Allison. The conversion to DocBook for
421 Samba 2.2 was done by Gerald Carter</para>