SMBD(8) UNIX System V (19 November 2002) SMBD(8)
NAME
smbd - server to provide SMB/CIFS services to clients
SYNOPSIS
smbd [ -D ] [ -a ] [ -i ] [ -o ] [ -P ] [ -h ] [ -V ]
[ -d <debug level> ] [ -l <log directory> ] [ -p <port
number> ] [ -O <socket option> ] [ -s <configuration file>
]
DESCRIPTION
This program is part of the Samba suite.
smbd 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.
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
smb.conf(5)
This man page will not describe the services, but will
concentrate on the administrative aspects of running the
server.
Please note that there are significant security implications
to running this server, and the smb.conf(5) manpage should
be regarded as mandatory reading before proceeding with
installation.
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.
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 smbd killed and
restarted.
OPTIONS
-D 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
Page 1 (printed 2/13/04)
SMBD(8) UNIX System V (19 November 2002) SMBD(8)
appropriate port. Operating the server as a daemon is
the recommended way of running smbd for servers that
provide more than casual use file and print services.
This switch is assumed if smbd is executed on the
command line of a shell.
-a If this parameter is specified, each new connection
will append log messages to the log file. This is the
default.
-i 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 deamon mode
when run from the command line.
-o If this parameter is specified, the log files will be
overwritten when opened. By default, smbd will append
entries to the log files.
-P Passive option. Causes smbd not to send any network
traffic out. Used for debugging by the developers only.
-h Prints the help information (usage) for smbd.
-v Prints the version number for smbd.
-d <debug level>
debuglevel is an integer from 0 to 10. The default
value if this parameter is not specified is zero.
The higher this value, the more detail will be logged
to the log files about the activities of the server. At
level 0, only critical errors and serious warnings will
be logged. Level 1 is a reasonable level for day to day
running - it generates a small amount of information
about operations carried out.
Levels above 1 will generate considerable amounts of
log data, and should only be used when investigating a
problem. Levels above 3 are designed for use only by
developers and generate HUGE amounts of log data, most
of which is extremely cryptic.
Note that specifying this parameter here will override
the log level file.
-l <log directory>
If specified, log directory specifies a log directory
into which the "log.smbd" log file will be created for
informational and debug messages from the running
server. The log file generated is never removed by the
Page 2 (printed 2/13/04)
SMBD(8) UNIX System V (19 November 2002) SMBD(8)
server although its size may be controlled by the max
log size option in the smb.conf(5) file. Beware: If
the directory specified does not exist, smbd will log
to the default debug log location defined at compile
time.
The default log directory is specified at compile time.
-O <socket options>
See the socket options parameter in the smb.conf(5)
file for details.
-p <port number>
port number is a positive integer value. The default
value if this parameter is not specified is 139.
This number is the port number that will be used when
making connections to the server from client software.
The standard (well-known) port number for the SMB over
TCP is 139, hence the default. If you wish to run the
server as an ordinary user rather than as root, most
systems will require you to use a port number greater
than 1024 - ask your system administrator for help if
you are in this situation.
In order for the server to be useful by most clients,
should you configure it on a port other than 139, you
will require port redirection services on port 139,
details of which are outlined in rfc1002.txt section
4.3.5.
This parameter is not normally specified except in the
above situation.
-s <configuration file>
The file specified contains the configuration details
required by the server. The information in this file
includes server-specific information such as what
printcap file to use, as well as descriptions of all
the services that the server is to provide. See
smb.conf(5) for more information. The default
configuration file name is determined at compile time.
FILES
/etc/inetd.conf
If the server is to be run by the inetd meta-daemon,
this file must contain suitable startup information for
the meta-daemon. See the UNIX_INSTALL.html document for
details.
/etc/rc
or whatever initialization script your system uses).
Page 3 (printed 2/13/04)
SMBD(8) UNIX System V (19 November 2002) SMBD(8)
If running the server as a daemon at startup, this file
will need to contain an appropriate startup sequence
for the server. See the UNIX_INSTALL.html document for
details.
/etc/services
If running the server via the meta-daemon inetd, 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). See the UNIX_INSTALL.html document
for details.
/usr/local/samba/lib/smb.conf
This is the default location of the smb.conf server
configuration file. Other common places that systems
install this file are /usr/samba/lib/smb.conf and
/etc/smb.conf.
This file describes all the services the server is to
make available to clients. See smb.conf(5) for more
information.
LIMITATIONS
On some systems smbd 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.
ENVIRONMENT VARIABLES
PRINTER
If no printer name is specified to printable services,
most systems will use the value of this variable (or lp
if this variable is not defined) as the name of the
printer to use. This is not specific to the server,
however.
PAM INTERACTION
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 obey pam restricions smb.conf
paramater. When this is set, the following restrictions
apply:
o Account Validation: All acccesses to a samba server are
checked against PAM to see if the account is vaild, not
disabled and is permitted to login at this time. This also
applies to encrypted logins.
Page 4 (printed 2/13/04)
SMBD(8) UNIX System V (19 November 2002) SMBD(8)
o Session Management: When not using share level secuirty,
users must pass PAM's session checks before access is
granted. Note however, that this is bypassed in share
level secuirty. Note also that some older pam
configuration files may need a line added for session
support.
VERSION
This man page is correct for version 2.2 of the Samba suite.
TROUBLESHOOTING
One of the common causes of difficulty when installing Samba
and SWAT is the existsnece of some type of firewall or port
filtering software on the Samba server. Make sure that the
appropriate ports outlined in this man page are available on
the server and are not currently being blocked by some type
of security software such as iptables or "port sentry". For
more troubleshooting information, refer to the additional
documentation included in the Samba distribution.
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.
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.
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.
SIGNALS
Sending the smbd a SIGHUP will cause it to reload its
smb.conf configuration file within a short period of time.
To shut down a user's smbd process it is recommended that
SIGKILL (-9) NOT 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 smbd is to send it a SIGTERM
(-15) signal and wait for it to die on its own.
The debug log level of smbd may be raised or lowered using
smbcontrol(1)
program (SIGUSR[1|2] signals are no longer used in Samba
2.2). This is to allow transient problems to be diagnosed,
whilst still running at a normally low log level.
Page 5 (printed 2/13/04)
SMBD(8) UNIX System V (19 November 2002) SMBD(8)
Note that as the signal handlers send a debug write, they
are not re-entrant in smbd. This you should wait until smbd
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.
SEE ALSO
hosts_access(5), inetd(8), nmbd(8)smb.conf(5)smbclient(1)
and the Internet RFC's rfc1001.txt, rfc1002.txt. In
addition the CIFS (formerly SMB) specification is available
as a link from the Web page http://samba.org/cifs/
<URL:http://samba.org/cifs/>.
AUTHOR
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.
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
ftp://ftp.icce.rug.nl/pub/unix/
<URL:ftp://ftp.icce.rug.nl/pub/unix/>) and updated for the
Samba 2.0 release by Jeremy Allison. The conversion to
DocBook for Samba 2.2 was done by Gerald Carter
Page 6 (printed 2/13/04)
