1SMBD(8) System Administration tools SMBD(8)
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6 smbd - server to provide SMB/CIFS services to clients
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9 smbd [-D|--daemon] [-F|--foreground] [-S|--log-stdout]
10 [-i|--interactive] [-V] [-b|--build-options] [-d <debug level>]
11 [-l|--log-basename <log directory>] [-p <port number(s)>]
12 [-P <profiling level>] [-s <configuration file>] [--no-process-group]
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15 This program is part of the samba(7) suite.
16 smbd is the server daemon that provides filesharing and printing
18 services to Windows clients. The server provides filespace and printer
19 services to clients using the SMB (or CIFS) protocol. This is
20 compatible with the LanManager protocol, and can service LanManager
21 clients. These include MSCLIENT 3.0 for DOS, Windows for Workgroups,
22 Windows 95/98/ME, Windows NT, Windows 2000, OS/2, DAVE for Macintosh,
23 and smbfs for Linux.
24 An extensive description of the services that the server can provide is
26 given in the man page for the configuration file controlling the
27 attributes of those services (see smb.conf(5). This man page will not
28 describe the services, but will concentrate on the administrative
29 aspects of running the server.
30 Please note that there are significant security implications to running
32 this server, and the smb.conf(5) manual page should be regarded as
33 mandatory reading before proceeding with installation.
34 A session is created whenever a client requests one. Each client gets a
36 copy of the server for each session. This copy then services all
37 connections made by the client during that session. When all
38 connections from its client are closed, the copy of the server for that
39 client terminates.
40 The configuration file, and any files that it includes, are
42 automatically reloaded every minute, if they change. You can force a
43 reload by sending a SIGHUP to the server. Reloading the configuration
44 file will not affect connections to any service that is already
45 established. Either the user will have to disconnect from the service,
46 or smbd killed and restarted.
47
49 -D|--daemon
50 If specified, this parameter causes the server to operate as a
51 daemon. That is, it detaches itself and runs in the background,
52 fielding requests on the appropriate port. Operating the server as
53 a daemon is the recommended way of running smbd for servers that
54 provide more than casual use file and print services. This switch
55 is assumed if smbd is executed on the command line of a shell.
56 -F|--foreground
58 If specified, this parameter causes the main smbd process to not
59 daemonize, i.e. double-fork and disassociate with the terminal.
60 Child processes are still created as normal to service each
61 connection request, but the main process does not exit. This
62 operation mode is suitable for running smbd under process
63 supervisors such as supervise and svscan from Daniel J. Bernstein's
64 daemontools package, or the AIX process monitor.
65 -S|--log-stdout
67 If specified, this parameter causes smbd to log to standard output
68 rather than a file.
69 -i|--interactive
71 If this parameter is specified it causes the server to run
72 "interactively", not as a daemon, even if the server is executed on
73 the command line of a shell. Setting this parameter negates the
74 implicit daemon mode when run from the command line. smbd will
75 only accept one connection and terminate. It will also log to
76 standard output, as if the -S parameter had been given.
77 -d|--debuglevel=level
79 level is an integer from 0 to 10. The default value if this
80 parameter is not specified is 0.
81 The higher this value, the more detail will be logged to the log
83 files about the activities of the server. At level 0, only critical
84 errors and serious warnings will be logged. Level 1 is a reasonable
85 level for day-to-day running - it generates a small amount of
86 information about operations carried out.
87 Levels above 1 will generate considerable amounts of log data, and
89 should only be used when investigating a problem. Levels above 3
90 are designed for use only by developers and generate HUGE amounts
91 of log data, most of which is extremely cryptic.
92 Note that specifying this parameter here will override the log
94 level parameter in the smb.conf file.
95 -V|--version
97 Prints the program version number.
98 -s|--configfile=<configuration file>
100 The file specified contains the configuration details required by
101 the server. The information in this file includes server-specific
102 information such as what printcap file to use, as well as
103 descriptions of all the services that the server is to provide. See
104 smb.conf for more information. The default configuration file name
105 is determined at compile time.
106 -l|--log-basename=logdirectory
108 Base directory name for log/debug files. The extension ".progname"
109 will be appended (e.g. log.smbclient, log.smbd, etc...). The log
110 file is never removed by the client.
111 --option=<name>=<value>
113 Set the smb.conf(5) option "<name>" to value "<value>" from the
114 command line. This overrides compiled-in defaults and options read
115 from the configuration file.
116 -?|--help
118 Print a summary of command line options.
119 --usage
121 Display brief usage message.
122 --no-process-group
124 Do not create a new process group for smbd.
125 -b|--build-options
127 Prints information about how Samba was built.
128 -p|--port<port number(s)>
130 port number(s) is a space or comma-separated list of TCP ports smbd
131 should listen on. The default value is taken from the ports
132 parameter in smb.conf
133 The default ports are 139 (used for SMB over NetBIOS over TCP) and
135 port 445 (used for plain SMB over TCP).
136 -P|--profiling-level<profiling level>
138 profiling level is a number specifying the level of profiling data
139 to be collected. 0 turns off profiling, 1 turns on counter
140 profiling only, 2 turns on complete profiling, and 3 resets all
141 profiling data.
142
144 /etc/inetd.conf
145 If the server is to be run by the inetd meta-daemon, this file must
146 contain suitable startup information for the meta-daemon.
147 /etc/rc
149 or whatever initialization script your system uses).
150 If running the server as a daemon at startup, this file will need
152 to contain an appropriate startup sequence for the server.
153 /etc/services
155 If running the server via the meta-daemon inetd, this file must
156 contain a mapping of service name (e.g., netbios-ssn) to service
157 port (e.g., 139) and protocol type (e.g., tcp).
158 /usr/local/samba/lib/smb.conf
160 This is the default location of the smb.conf(5) server
161 configuration file. Other common places that systems install this
162 file are /usr/samba/lib/smb.conf and /etc/samba/smb.conf.
163 This file describes all the services the server is to make
165 available to clients. See smb.conf(5) for more information.
166
168 On some systems smbd cannot change uid back to root after a setuid()
169 call. Such systems are called trapdoor uid systems. If you have such a
170 system, you will be unable to connect from a client (such as a PC) as
171 two different users at once. Attempts to connect the second user will
172 result in access denied or similar.
173
175 PRINTER
176 If no printer name is specified to printable services, most systems
177 will use the value of this variable (or lp if this variable is not
178 defined) as the name of the printer to use. This is not specific to
179 the server, however.
180
182 Samba uses PAM for authentication (when presented with a plaintext
183 password), for account checking (is this account disabled?) and for
184 session management. The degree too which samba supports PAM is
185 restricted by the limitations of the SMB protocol and the obey pam
186 restrictions smb.conf(5) parameter. When this is set, the following
187 restrictions apply:
188 · Account Validation: All accesses to a samba server are
190 checked against PAM to see if the account is valid, not
191 disabled and is permitted to login at this time. This also
192 applies to encrypted logins.
193 · Session Management: When not using share level security,
195 users must pass PAM's session checks before access is
196 granted. Note however, that this is bypassed in share level
197 security. Note also that some older pam configuration files
198 may need a line added for session support.
199
201 This man page is part of version 4.9.1 of the Samba suite.
202
204 Most diagnostics issued by the server are logged in a specified log
205 file. The log file name is specified at compile time, but may be
206 overridden on the command line.
207 The number and nature of diagnostics available depends on the debug
209 level used by the server. If you have problems, set the debug level to
210 3 and peruse the log files.
211 Most messages are reasonably self-explanatory. Unfortunately, at the
213 time this man page was created, there are too many diagnostics
214 available in the source code to warrant describing each and every
215 diagnostic. At this stage your best bet is still to grep the source
216 code and inspect the conditions that gave rise to the diagnostics you
217 are seeing.
218
220 Samba stores it's data in several TDB (Trivial Database) files, usually
221 located in /var/lib/samba.
222 (*) information persistent across restarts (but not necessarily
224 important to backup).
225 account_policy.tdb*
227 NT account policy settings such as pw expiration, etc...
228 brlock.tdb
230 byte range locks
231 browse.dat
233 browse lists
234 gencache.tdb
236 generic caching db
237 group_mapping.tdb*
239 group mapping information
240 locking.tdb
242 share modes & oplocks
243 login_cache.tdb*
245 bad pw attempts
246 messages.tdb
248 Samba messaging system
249 netsamlogon_cache.tdb*
251 cache of user net_info_3 struct from net_samlogon() request (as a
252 domain member)
253 ntdrivers.tdb*
255 installed printer drivers
256 ntforms.tdb*
258 installed printer forms
259 ntprinters.tdb*
261 installed printer information
262 printing/
264 directory containing tdb per print queue of cached lpq output
265 registry.tdb
267 Windows registry skeleton (connect via regedit.exe)
268 smbXsrv_session_global.tdb
270 session information (e.g. support for 'utmp = yes')
271 smbXsrv_tcon_global.tdb
273 share connections (used to enforce max connections, etc...)
274 smbXsrv_open_global.tdb
276 open file handles (used durable handles, etc...)
277 share_info.tdb*
279 share acls
280 winbindd_cache.tdb
282 winbindd's cache of user lists, etc...
283 winbindd_idmap.tdb*
285 winbindd's local idmap db
286 wins.dat*
288 wins database when 'wins support = yes'
289
291 Sending the smbd a SIGHUP will cause it to reload its smb.conf
292 configuration file within a short period of time.
293 To shut down a user's smbd process it is recommended that SIGKILL (-9)
295 NOT be used, except as a last resort, as this may leave the shared
296 memory area in an inconsistent state. The safe way to terminate an smbd
297 is to send it a SIGTERM (-15) signal and wait for it to die on its own.
298 The debug log level of smbd may be raised or lowered using
300 smbcontrol(1) program (SIGUSR[1|2] signals are no longer used since
301 Samba 2.2). This is to allow transient problems to be diagnosed, whilst
302 still running at a normally low log level.
303 Note that as the signal handlers send a debug write, they are not
305 re-entrant in smbd. This you should wait until smbd is in a state of
306 waiting for an incoming SMB before issuing them. It is possible to make
307 the signal handlers safe by un-blocking the signals before the select
308 call and re-blocking them after, however this would affect performance.
309
311 hosts_access(5), inetd(8), nmbd(8), smb.conf(5), smbclient(1),
312 testparm(1), and the Internet RFC's rfc1001.txt, rfc1002.txt. In
313 addition the CIFS (formerly SMB) specification is available as a link
314 from the Web page https://www.samba.org/cifs/.
315
317 The original Samba software and related utilities were created by
318 Andrew Tridgell. Samba is now developed by the Samba Team as an Open
319 Source project similar to the way the Linux kernel is developed.
320Samba 4.9.1 05/11/2019 SMBD(8)