NAME
smbd - server to provide SMB/CIFS services to clients
SYNOPSIS
smbd [-D] [-F] [-S] [-i] [-h] [-V] [-b] [-d <debug level>]
[-l <log directory>] [-p <port number(s)>] [-P <profiling level>]
[-O <socket option>] [-s <configuration file>]
DESCRIPTION
This program is part of the samba(7) 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) manual page 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 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.
-F
If specified, this parameter causes the main smbd process to not
daemonize, i.e. double-fork and disassociate with the terminal.
Child processes are still created as normal to service each
connection request, but the main process does not exit. This
operation mode is suitable for running smbd under process
supervisors such as supervise and svscan from Daniel J. Bernstein's
daemontools package, or the AIX process monitor.
-S
If specified, this parameter causes smbd to log to standard output
rather than a file.
-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 daemon mode when run from the command line. smbd also
logs to standard output, as if the -S parameter had been given.
-d|--debuglevel=level
level is an integer from 0 to 10. The default value if this
parameter is not specified is 0.
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
smb.conf.html# parameter in the smb.conf file.
-V|--version
Prints the program version number.
-s|--configfile <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 for more information. The default configuration file name
is determined at compile time.
-l|--log-basename=logdirectory
Base directory name for log/debug files. The extension ".progname"
will be appended (e.g. log.smbclient, log.smbd, etc...). The log
file is never removed by the client.
-h|--help
Print a summary of command line options.
-b
Prints information about how Samba was built.
-p|--port<port number(s)>
port number(s) is a space or comma-separated list of TCP ports smbd
should listen on. The default value is taken from the ports
parameter in smb.conf
The default ports are 139 (used for SMB over NetBIOS over TCP) and
port 445 (used for plain SMB over TCP).
-P|--profiling-level<profiling level>
profiling level is a number specifying the level of profiling data
to be collected. 0 turns off profiling, 1 turns on counter
profiling only, 2 turns on complete profiling, and 3 resets all
profiling data.
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.
/etc/rc
or whatever initialization script your system uses).
If running the server as a daemon at startup, this file will need
to contain an appropriate startup sequence for the server.
/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).
/etc/samba/smb.conf
This is the default location of the smb.conf(5) +server
configuration file.
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
restrictions smb.conf(5) paramater. When this is set, the following
restrictions apply:
o Account Validation: All accesses 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.
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 3 of the Samba suite.
DIAGNOSTICS
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.
TDB FILES
Samba stores it's data in several TDB (Trivial Database) files, usually
located in /var/lib/samba.
(*) information persistent across restarts (but not necessarily
important to backup).
account_policy.tdb*
NT account policy settings such as pw expiration, etc...
brlock.tdb
byte range locks
browse.dat
browse lists
connections.tdb
share connections (used to enforce max connections, etc...)
gencache.tdb
generic caching db
group_mapping.tdb*
group mapping information
locking.tdb
share modes & oplocks
login_cache.tdb*
bad pw attempts
messages.tdb
Samba messaging system
netsamlogon_cache.tdb*
cache of user net_info_3 struct from net_samlogon() request (as a
domain member)
ntdrivers.tdb*
installed printer drivers
ntforms.tdb*
installed printer forms
ntprinters.tdb*
installed printer information
printing/
directory containing tdb per print queue of cached lpq output
registry.tdb
Windows registry skeleton (connect via regedit.exe)
sessionid.tdb
session information (e.g. support for 'utmp = yes')
share_info.tdb*
share acls
winbindd_cache.tdb
winbindd's cache of user lists, etc...
winbindd_idmap.tdb*
winbindd's local idmap db
wins.dat*
wins database when 'wins support = yes'
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 since
Samba 2.2). This is to allow transient problems to be diagnosed, whilst
still running at a normally low log level.
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),
testparm(1), testprns(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/.
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/) and
updated for the Samba 2.0 release by Jeremy Allison. The conversion to
DocBook for Samba 2.2 was done by Gerald Carter. The conversion to
DocBook XML 4.2 for Samba 3.0 was done by Alexander Bokovoy.