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2 <!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
6 <refentrytitle>smbd</refentrytitle>
7 <manvolnum>8</manvolnum>
8 <refmiscinfo class="source">Samba</refmiscinfo>
9 <refmiscinfo class="manual">System Administration tools</refmiscinfo>
10 <refmiscinfo class="version">4.6</refmiscinfo>
15 <refname>smbd</refname>
16 <refpurpose>server to provide SMB/CIFS services to clients</refpurpose>
21 <command>smbd</command>
22 <arg choice="opt">-D|--daemon</arg>
23 <arg choice="opt">-F|--foreground</arg>
24 <arg choice="opt">-S|--log-stdout</arg>
25 <arg choice="opt">-i|--interactive</arg>
26 <arg choice="opt">-V</arg>
27 <arg choice="opt">-b|--build-options</arg>
28 <arg choice="opt">-d <debug level></arg>
29 <arg choice="opt">-l|--log-basename <log directory></arg>
30 <arg choice="opt">-p <port number(s)></arg>
31 <arg choice="opt">-P <profiling level></arg>
32 <arg choice="opt">-s <configuration file></arg>
33 <arg choice="opt">--no-process-group</arg>
38 <title>DESCRIPTION</title>
39 <para>This program is part of the <citerefentry><refentrytitle>samba</refentrytitle>
40 <manvolnum>7</manvolnum></citerefentry> suite.</para>
42 <para><command>smbd</command> is the server daemon that
43 provides filesharing and printing services to Windows clients.
44 The server provides filespace and printer services to
45 clients using the SMB (or CIFS) protocol. This is compatible
46 with the LanManager protocol, and can service LanManager
47 clients. These include MSCLIENT 3.0 for DOS, Windows for
48 Workgroups, Windows 95/98/ME, Windows NT, Windows 2000,
49 OS/2, DAVE for Macintosh, and smbfs for Linux.</para>
51 <para>An extensive description of the services that the
52 server can provide is given in the man page for the
53 configuration file controlling the attributes of those
54 services (see <citerefentry><refentrytitle>smb.conf</refentrytitle>
55 <manvolnum>5</manvolnum></citerefentry>. This man page will not describe the
56 services, but will concentrate on the administrative aspects
57 of running the server.</para>
59 <para>Please note that there are significant security
60 implications to running this server, and the <citerefentry><refentrytitle>smb.conf</refentrytitle>
61 <manvolnum>5</manvolnum></citerefentry> manual page should be regarded as mandatory reading before
62 proceeding with installation.</para>
64 <para>A session is created whenever a client requests one.
65 Each client gets a copy of the server for each session. This
66 copy then services all connections made by the client during
67 that session. When all connections from its client are closed,
68 the copy of the server for that client terminates.</para>
70 <para>The configuration file, and any files that it includes,
71 are automatically reloaded every minute, if they change. You
72 can force a reload by sending a SIGHUP to the server. Reloading
73 the configuration file will not affect connections to any service
74 that is already established. Either the user will have to
75 disconnect from the service, or <command>smbd</command> killed and restarted.</para>
79 <title>OPTIONS</title>
83 <term>-D|--daemon</term>
84 <listitem><para>If specified, this parameter causes
85 the server to operate as a daemon. That is, it detaches
86 itself and runs in the background, fielding requests
87 on the appropriate port. Operating the server as a
88 daemon is the recommended way of running <command>smbd</command> for
89 servers that provide more than casual use file and
90 print services. This switch is assumed if <command>smbd
91 </command> is executed on the command line of a shell.
96 <term>-F|--foreground</term>
97 <listitem><para>If specified, this parameter causes
98 the main <command>smbd</command> process to not daemonize,
99 i.e. double-fork and disassociate with the terminal.
100 Child processes are still created as normal to service
101 each connection request, but the main process does not
102 exit. This operation mode is suitable for running
103 <command>smbd</command> under process supervisors such
104 as <command>supervise</command> and <command>svscan</command>
105 from Daniel J. Bernstein's <command>daemontools</command>
106 package, or the AIX process monitor.
111 <term>-S|--log-stdout</term>
112 <listitem><para>If specified, this parameter causes
113 <command>smbd</command> to log to standard output rather
114 than a file.</para></listitem>
118 <term>-i|--interactive</term>
119 <listitem><para>If this parameter is specified it causes the
120 server to run "interactively", not as a daemon, even if the
121 server is executed on the command line of a shell. Setting this
122 parameter negates the implicit daemon mode when run from the
123 command line. <command>smbd</command> will only accept one
124 connection and terminate. It will also log to standard output,
125 as if the <command>-S</command> parameter had been given.
129 &stdarg.server.debug;
134 <term>--no-process-group</term>
135 <listitem><para>Do not create a new process group for smbd.
140 <term>-b|--build-options</term>
141 <listitem><para>Prints information about how
142 Samba was built.</para></listitem>
146 <term>-p|--port<port number(s)></term>
147 <listitem><para><replaceable>port number(s)</replaceable> is a
148 space or comma-separated list of TCP ports smbd should listen on.
149 The default value is taken from the <smbconfoption name="ports"/> parameter in &smb.conf;</para>
151 <para>The default ports are 139 (used for SMB over NetBIOS over TCP)
152 and port 445 (used for plain SMB over TCP).
157 <term>-P|--profiling-level<profiling level></term>
158 <listitem><para><replaceable>profiling level</replaceable> is a
159 number specifying the level of profiling data to be collected.
160 0 turns off profiling, 1 turns on counter profiling only,
161 2 turns on complete profiling, and 3 resets all profiling data.
172 <term><filename>/etc/inetd.conf</filename></term>
173 <listitem><para>If the server is to be run by the
174 <command>inetd</command> meta-daemon, this file
175 must contain suitable startup information for the
181 <term><filename>/etc/rc</filename></term>
182 <listitem><para>or whatever initialization script your
185 <para>If running the server as a daemon at startup,
186 this file will need to contain an appropriate startup
187 sequence for the server. </para></listitem>
191 <term><filename>/etc/services</filename></term>
192 <listitem><para>If running the server via the
193 meta-daemon <command>inetd</command>, this file
194 must contain a mapping of service name (e.g., netbios-ssn)
195 to service port (e.g., 139) and protocol type (e.g., tcp).
200 <term><filename>/usr/local/samba/lib/smb.conf</filename></term>
201 <listitem><para>This is the default location of the <citerefentry><refentrytitle>smb.conf</refentrytitle>
202 <manvolnum>5</manvolnum></citerefentry> server configuration file. Other common places that systems
203 install this file are <filename>/usr/samba/lib/smb.conf</filename>
204 and <filename>/etc/samba/smb.conf</filename>.</para>
206 <para>This file describes all the services the server
207 is to make available to clients. See <citerefentry><refentrytitle>smb.conf</refentrytitle>
208 <manvolnum>5</manvolnum></citerefentry> for more information.</para>
215 <title>LIMITATIONS</title>
216 <para>On some systems <command>smbd</command> cannot change uid back
217 to root after a setuid() call. Such systems are called
218 trapdoor uid systems. If you have such a system,
219 you will be unable to connect from a client (such as a PC) as
220 two different users at once. Attempts to connect the
221 second user will result in access denied or
226 <title>ENVIRONMENT VARIABLES</title>
230 <term><envar>PRINTER</envar></term>
231 <listitem><para>If no printer name is specified to
232 printable services, most systems will use the value of
233 this variable (or <constant>lp</constant> if this variable is
234 not defined) as the name of the printer to use. This
235 is not specific to the server, however.</para></listitem>
242 <title>PAM INTERACTION</title>
243 <para>Samba uses PAM for authentication (when presented with a plaintext
244 password), for account checking (is this account disabled?) and for
245 session management. The degree too which samba supports PAM is restricted
246 by the limitations of the SMB protocol and the <smbconfoption name="obey pam restrictions"/> <citerefentry><refentrytitle>smb.conf</refentrytitle>
247 <manvolnum>5</manvolnum></citerefentry> parameter. When this is set, the following restrictions apply:
251 <listitem><para><emphasis>Account Validation</emphasis>: All accesses to a
252 samba server are checked
253 against PAM to see if the account is valid, not disabled and is permitted to
254 login at this time. This also applies to encrypted logins.
257 <listitem><para><emphasis>Session Management</emphasis>: When not using share
258 level security, users must pass PAM's session checks before access
259 is granted. Note however, that this is bypassed in share level security.
260 Note also that some older pam configuration files may need a line
261 added for session support.
267 <title>VERSION</title>
269 <para>This man page is correct for version 3 of
270 the Samba suite.</para>
274 <title>DIAGNOSTICS</title>
276 <para>Most diagnostics issued by the server are logged
277 in a specified log file. The log file name is specified
278 at compile time, but may be overridden on the command line.</para>
280 <para>The number and nature of diagnostics available depends
281 on the debug level used by the server. If you have problems, set
282 the debug level to 3 and peruse the log files.</para>
284 <para>Most messages are reasonably self-explanatory. Unfortunately,
285 at the time this man page was created, there are too many diagnostics
286 available in the source code to warrant describing each and every
287 diagnostic. At this stage your best bet is still to grep the
288 source code and inspect the conditions that gave rise to the
289 diagnostics you are seeing.</para>
293 <title>TDB FILES</title>
295 <para>Samba stores it's data in several TDB (Trivial Database) files, usually located in <filename>/var/lib/samba</filename>.</para>
298 (*) information persistent across restarts (but not
299 necessarily important to backup).
303 <varlistentry><term>account_policy.tdb*</term>
305 <para>NT account policy settings such as pw expiration, etc...</para>
309 <varlistentry><term>brlock.tdb</term>
310 <listitem><para>byte range locks</para></listitem>
313 <varlistentry><term>browse.dat</term>
314 <listitem><para>browse lists</para></listitem>
317 <varlistentry><term>gencache.tdb</term>
318 <listitem><para>generic caching db</para></listitem>
321 <varlistentry><term>group_mapping.tdb*</term>
322 <listitem><para>group mapping information</para></listitem>
325 <varlistentry><term>locking.tdb</term>
326 <listitem><para>share modes & oplocks</para></listitem>
329 <varlistentry><term>login_cache.tdb*</term>
330 <listitem><para>bad pw attempts</para></listitem>
333 <varlistentry><term>messages.tdb</term>
334 <listitem><para>Samba messaging system</para></listitem>
337 <varlistentry><term>netsamlogon_cache.tdb*</term>
338 <listitem><para>cache of user net_info_3 struct from net_samlogon() request (as a domain member)</para></listitem>
341 <varlistentry><term>ntdrivers.tdb*</term>
342 <listitem><para>installed printer drivers</para></listitem>
345 <varlistentry><term>ntforms.tdb*</term>
346 <listitem><para>installed printer forms</para></listitem>
349 <varlistentry><term>ntprinters.tdb*</term>
350 <listitem><para>installed printer information</para></listitem>
353 <varlistentry><term>printing/</term>
354 <listitem><para>directory containing tdb per print queue of cached lpq output</para></listitem>
357 <varlistentry><term>registry.tdb</term>
358 <listitem><para>Windows registry skeleton (connect via regedit.exe)</para></listitem>
361 <varlistentry><term>smbXsrv_session_global.tdb</term>
362 <listitem><para>session information (e.g. support for 'utmp = yes')</para></listitem>
365 <varlistentry><term>smbXsrv_tcon_global.tdb</term>
366 <listitem><para>share connections (used to enforce max connections, etc...)</para></listitem>
369 <varlistentry><term>smbXsrv_open_global.tdb</term>
370 <listitem><para>open file handles (used durable handles, etc...)</para></listitem>
373 <varlistentry><term>share_info.tdb*</term>
374 <listitem><para>share acls</para></listitem>
377 <varlistentry><term>winbindd_cache.tdb</term>
378 <listitem><para>winbindd's cache of user lists, etc...</para></listitem>
381 <varlistentry><term>winbindd_idmap.tdb*</term>
382 <listitem><para>winbindd's local idmap db</para></listitem>
385 <varlistentry><term>wins.dat*</term>
386 <listitem><para>wins database when 'wins support = yes'</para></listitem>
394 <title>SIGNALS</title>
396 <para>Sending the <command>smbd</command> a SIGHUP will cause it to
397 reload its <filename>smb.conf</filename> configuration
398 file within a short period of time.</para>
400 <para>To shut down a user's <command>smbd</command> process it is recommended
401 that <command>SIGKILL (-9)</command> <emphasis>NOT</emphasis>
402 be used, except as a last resort, as this may leave the shared
403 memory area in an inconsistent state. The safe way to terminate
404 an <command>smbd</command> is to send it a SIGTERM (-15) signal and wait for
405 it to die on its own.</para>
407 <para>The debug log level of <command>smbd</command> may be raised
408 or lowered using <citerefentry><refentrytitle>smbcontrol</refentrytitle>
409 <manvolnum>1</manvolnum></citerefentry> program (SIGUSR[1|2] signals are no longer
410 used since Samba 2.2). This is to allow transient problems to be diagnosed,
411 whilst still running at a normally low log level.</para>
413 <para>Note that as the signal handlers send a debug write,
414 they are not re-entrant in <command>smbd</command>. This you should wait until
415 <command>smbd</command> is in a state of waiting for an incoming SMB before
416 issuing them. It is possible to make the signal handlers safe
417 by un-blocking the signals before the select call and re-blocking
418 them after, however this would affect performance.</para>
422 <title>SEE ALSO</title>
423 <para><citerefentry><refentrytitle>hosts_access</refentrytitle>
424 <manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>inetd</refentrytitle>
425 <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>nmbd</refentrytitle>
426 <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>smb.conf</refentrytitle>
427 <manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>smbclient</refentrytitle>
428 <manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>testparm</refentrytitle>
429 <manvolnum>1</manvolnum></citerefentry>, and the
430 Internet RFC's <filename>rfc1001.txt</filename>, <filename>rfc1002.txt</filename>.
431 In addition the CIFS (formerly SMB) specification is available
432 as a link from the Web page <ulink noescape="1" url="https://www.samba.org/cifs/">
433 https://www.samba.org/cifs/</ulink>.</para>
437 <title>AUTHOR</title>
439 <para>The original Samba software and related utilities
440 were created by Andrew Tridgell. Samba is now developed
441 by the Samba Team as an Open Source project similar
442 to the way the Linux kernel is developed.</para>
444 <para>The original Samba man pages were written by Karl Auer.
445 The man page sources were converted to YODL format (another
446 excellent piece of Open Source software, available at <ulink url="ftp://ftp.icce.rug.nl/pub/unix/">
447 ftp://ftp.icce.rug.nl/pub/unix/</ulink>) and updated for the Samba 2.0
448 release by Jeremy Allison. The conversion to DocBook for
449 Samba 2.2 was done by Gerald Carter. The conversion to DocBook XML 4.2 for
450 Samba 3.0 was done by Alexander Bokovoy.</para>