rsyncd.conf
rsyncd.conf(5) rsyncd.conf(5)
NAME
rsyncd.conf - configuration file for rsync server
SYNOPSIS
rsyncd.conf
DESCRIPTION
The rsyncd.conf file is the runtime configuration file for rsync when
run as an rsync server.
The rsyncd.conf file controls authentication, access, logging and
available modules.
FILE FORMAT
The file consists of modules and parameters. A module begins with the
name of the module in square brackets and continues until the next
module begins. Modules contain parameters of the form ’name = value’.
The file is line-based - that is, each newline-terminated line repre-
sents either a comment, a module name or a parameter.
Only the first equals sign in a parameter is significant. Whitespace
before or after the first equals sign is discarded. Leading, trailing
and internal whitespace in module and parameter names is irrelevant.
Leading and trailing whitespace in a parameter value is discarded.
Internal whitespace within a parameter value is retained verbatim.
Any line beginning with a hash (#) is ignored, as are lines containing
only whitespace.
Any line ending in a \ is "continued" on the next line in the custom-
ary UNIX fashion.
The values following the equals sign in parameters are all either a
string (no quotes needed) or a boolean, which may be given as yes/no,
0/1 or true/false. Case is not significant in boolean values, but is
preserved in string values.
LAUNCHING THE RSYNC DAEMON
The rsync daemon is launched by specifying the --daemon option to
rsync.
The daemon must run with root privileges if you wish to use chroot, to
bind to a port numbered under 1024 (as is the default 873), or to set
file ownership. Otherwise, it must just have permission to read and
write the appropriate data, log, and lock files.
You can launch it either via inetd, as a stand-alone daemon, or from
an rsync client via a remote shell. If run as a stand-alone daemon
then just run the command "rsync --daemon" from a suitable startup
script. If run from an rsync client via a remote shell (by specifying
both the "-e/--rsh" option and server mode with "::" or "rsync://"),
the --daemon option is automatically passed to the remote side.
When run via inetd you should add a line like this to /etc/services:
rsync 873/tcp
and a single line something like this to /etc/inetd.conf:
rsync stream tcp nowait root /usr/bin/rsync rsyncd
--daemon
Replace "/usr/bin/rsync" with the path to where you have rsync
installed on your system. You will then need to send inetd a HUP sig-
nal to tell it to reread its config file.
Note that you should not send the rsync server a HUP signal to force
it to reread the rsyncd.conf file. The file is re-read on each client
connection.
GLOBAL OPTIONS
The first parameters in the file (before a [module] header) are the
global parameters.
You may also include any module parameters in the global part of the
config file in which case the supplied value will override the default
for that parameter.
motd file
The "motd file" option allows you to specify a "message of the
day" to display to clients on each connect. This usually con-
tains site information and any legal notices. The default is no
motd file.
log file
The "log file" option tells the rsync daemon to log messages to
that file rather than using syslog. This is particularly useful
on systems (such as AIX) where syslog() doesn’t work for
chrooted programs.
pid file
The "pid file" option tells the rsync daemon to write its pro-
cess ID to that file.
syslog facility
The "syslog facility" option allows you to specify the syslog
facility name to use when logging messages from the rsync
server. You may use any standard syslog facility name which is
defined on your system. Common names are auth, authpriv, cron,
daemon, ftp, kern, lpr, mail, news, security, syslog, user,
uucp, local0, local1, local2, local3, local4, local5, local6
and local7. The default is daemon.
socket options
This option can provide endless fun for people who like to tune
their systems to the utmost degree. You can set all sorts of
socket options which may make transfers faster (or slower!).
Read the man page for the setsockopt() system call for details
on some of the options you may be able to set. By default no
special socket options are set.
MODULE OPTIONS
After the global options you should define a number of modules, each
module exports a directory tree as a symbolic name. Modules are
exported by specifying a module name in square brackets [module] fol-
lowed by the options for that module.
comment
The "comment" option specifies a description string that is
displayed next to the module name when clients obtain a list of
available modules. The default is no comment.
path The "path" option specifies the directory in the servers
filesystem to make available in this module. You must specify
this option for each module in rsyncd.conf.
use chroot
If "use chroot" is true, the rsync server will chroot to the
"path" before starting the file transfer with the client. This
has the advantage of extra protection against possible imple-
mentation security holes, but it has the disadvantages of
requiring super-user privileges, of not being able to follow
symbolic links that are either absolute or outside of the new
root path, and of complicating the preservation of usernames
and groups (see below). When "use chroot" is false, for secu-
rity reasons, symlinks may only be relative paths pointing to
other files within the root path, and leading slashes are
removed from most absolute paths (options such as --backup-dir,
--compare-dest, etc. interpret an absolute path as rooted in
the module’s "path" dir, just as if chroot was specified). The
default for "use chroot" is true.
In order to preserve usernames and groupnames, rsync needs to
be able to use the standard library functions for looking up
names and IDs (i.e. getpwuid(), getgrgid(), getpwname(), and
getgrnam()). This means a process in the chroot namespace will
need to have access to the resources used by these library
functions (traditionally /etc/passwd and /etc/group). If these
resources are not available, rsync will only be able to copy
the IDs, just as if the --numeric-ids option had been speci-
fied.
Note that you are free to setup user/group information in the
chroot area differently from your normal system. For example,
you could abbreviate the list of users and groups. Also, you
can protect this information from being downloaded/uploaded by
adding an exclude rule to the rsync.conf file (e.g. "exclude =
/etc/"). Note that having the exclusion affect uploads is a
relatively new feature in rsync, so make sure your server is
running at least 2.6.3 to effect this.
max connections
The "max connections" option allows you to specify the maximum
number of simultaneous connections you will allow. Any clients
connecting when the maximum has been reached will receive a
message telling them to try later. The default is 0 which
means no limit. See also the "lock file" option.
lock file
The "lock file" option specifies the file to use to support the
"max connections" option. The rsync server uses record locking
on this file to ensure that the max connections limit is not
exceeded for the modules sharing the lock file. The default is
/var/run/rsyncd.lock.
read only
The "read only" option determines whether clients will be able
to upload files or not. If "read only" is true then any
attempted uploads will fail. If "read only" is false then
uploads will be possible if file permissions on the server
allow them. The default is for all modules to be read only.
write only
The "write only" option determines whether clients will be able
to download files or not. If "write only" is true then any
attempted downloads will fail. If "write only" is false then
downloads will be possible if file permissions on the server
allow them. The default is for this option to be disabled.
list The "list" option determines if this module should be listed
when the client asks for a listing of available modules. By
setting this to false you can create hidden modules. The
default is for modules to be listable.
uid The "uid" option specifies the user name or user ID that file
transfers to and from that module should take place as when the
daemon was run as root. In combination with the "gid" option
this determines what file permissions are available. The
default is uid -2, which is normally the user "nobody".
gid The "gid" option specifies the group name or group ID that file
transfers to and from that module should take place as when the
daemon was run as root. This complements the "uid" option. The
default is gid -2, which is normally the group "nobody".
exclude
The "exclude" option allows you to specify a space-separated
list of patterns that the server will not allow to be read or
written. This is only superficially equivalent to the client
specifying these patterns with the --exclude option. Only one
"exclude" option may be specified, but you can use "-" and "+"
before patterns to specify exclude/include.
Because this exclude list is not passed to the client it only
applies on the server: that is, it excludes files received by a
client when receiving from a server and files deleted on a
server when sending to a server, but it doesn’t exclude files
from being deleted on a client when receiving from a server.
exclude from
The "exclude from" option specifies a filename on the server
that contains exclude patterns, one per line. This is only
superficially equivalent to the client specifying the
--exclude-from option with an equivalent file. See the
"exclude" option above.
include
The "include" option allows you to specify a space-separated
list of patterns which rsync should not exclude. This is only
superficially equivalent to the client specifying these pat-
terns with the --include option because it applies only on the
server. This is useful as it allows you to build up quite com-
plex exclude/include rules. Only one "include" option may be
specified, but you can use "+" and "-" before patterns to
switch include/exclude. See the "exclude" option above.
include from
The "include from" option specifies a filename on the server
that contains include patterns, one per line. This is only
superficially equivalent to the client specifying the
--include-from option with a equivalent file. See the
"exclude" option above.
auth users
The "auth users" option specifies a comma and space-separated
list of usernames that will be allowed to connect to this mod-
ule. The usernames do not need to exist on the local system.
The usernames may also contain shell wildcard characters. If
"auth users" is set then the client will be challenged to sup-
ply a username and password to connect to the module. A chal-
lenge response authentication protocol is used for this
exchange. The plain text usernames are passwords are stored in
the file specified by the "secrets file" option. The default is
for all users to be able to connect without a password (this is
called "anonymous rsync").
See also the CONNECTING TO AN RSYNC SERVER OVER A REMOTE SHELL
PROGRAM section in rsync(1) for information on how handle an
rsyncd.conf-level username that differs from the remote-shell-
level username when using a remote shell to connect to an rsync
server.
secrets file
The "secrets file" option specifies the name of a file that
contains the username:password pairs used for authenticating
this module. This file is only consulted if the "auth users"
option is specified. The file is line based and contains user-
name:password pairs separated by a single colon. Any line
starting with a hash (#) is considered a comment and is
skipped. The passwords can contain any characters but be warned
that many operating systems limit the length of passwords that
can be typed at the client end, so you may find that passwords
longer than 8 characters don’t work.
There is no default for the "secrets file" option, you must
choose a name (such as /etc/rsyncd.secrets). The file must
normally not be readable by "other"; see "strict modes".
strict modes
The "strict modes" option determines whether or not the permis-
sions on the secrets file will be checked. If "strict modes"
is true, then the secrets file must not be readable by any user
ID other than the one that the rsync daemon is running under.
If "strict modes" is false, the check is not performed. The
default is true. This option was added to accommodate rsync
running on the Windows operating system.
hosts allow
The "hosts allow" option allows you to specify a list of pat-
terns that are matched against a connecting clients hostname
and IP address. If none of the patterns match then the connec-
tion is rejected.
Each pattern can be in one of five forms:
o a dotted decimal IPv4 address of the form a.b.c.d, or an IPv6
address of the form a:b:c::d:e:f. In this case the incoming
machine’s IP address must match exactly.
o an address/mask in the form ipaddr/n where ipaddr is the IP
address and n is the number of one bits in the netmask. All IP
addresses which match the masked IP address will be allowed in.
o an address/mask in the form ipaddr/maskaddr where ipaddr is the
IP address and maskaddr is the netmask in dotted decimal nota-
tion for IPv4, or similar for IPv6, e.g. ffff:ffff:ffff:ffff::
instead of /64. All IP addresses which match the masked IP
address will be allowed in.
o a hostname. The hostname as determined by a reverse lookup will
be matched (case insensitive) against the pattern. Only an
exact match is allowed in.
o a hostname pattern using wildcards. These are matched using the
same rules as normal unix filename matching. If the pattern
matches then the client is allowed in.
Note IPv6 link-local addresses can have a scope in the address
specification:
fe80::1%link1
fe80::%link1/64
fe80::%link1/ffff:ffff:ffff:ffff::
You can also combine "hosts allow" with a separate "hosts deny"
option. If both options are specified then the "hosts allow"
option s checked first and a match results in the client being
able to connect. The "hosts deny" option is then checked and a
match means that the host is rejected. If the host does not
match either the "hosts allow" or the "hosts deny" patterns
then it is allowed to connect.
The default is no "hosts allow" option, which means all hosts
can connect.
hosts deny
The "hosts deny" option allows you to specify a list of pat-
terns that are matched against a connecting clients hostname
and IP address. If the pattern matches then the connection is
rejected. See the "hosts allow" option for more information.
The default is no "hosts deny" option, which means all hosts
can connect.
ignore errors
The "ignore errors" option tells rsyncd to ignore I/O errors on
the server when deciding whether to run the delete phase of the
transfer. Normally rsync skips the --delete step if any I/O
errors have occurred in order to prevent disasterous deletion
due to a temporary resource shortage or other I/O error. In
some cases this test is counter productive so you can use this
option to turn off this behaviour.
ignore nonreadable
This tells the rsync server to completely ignore files that are
not readable by the user. This is useful for public archives
that may have some non-readable files among the directories,
and the sysadmin doesn’t want those files to be seen at all.
transfer logging
The "transfer logging" option enables per-file logging of down-
loads and uploads in a format somewhat similar to that used by
ftp daemons. If you want to customize the log formats look at
the log format option.
log format
The "log format" option allows you to specify the format used
for logging file transfers when transfer logging is enabled.
The format is a text string containing embedded single charac-
ter escape sequences prefixed with a percent (%) character.
The prefixes that are understood are:
o %h for the remote host name
o %a for the remote IP address
o %l for the length of the file in bytes
o %p for the process ID of this rsync session
o %o for the operation, which is either "send" or "recv"
o %f for the filename
o %P for the module path
o %m for the module name
o %t for the current date time
o %u for the authenticated username (or the null string)
o %b for the number of bytes actually transferred
o %c when sending files this gives the number of checksum bytes
received for this file
The default log format is "%o %h [%a] %m (%u) %f %l", and a "%t
[%p] " is always added to the beginning when using the "log
file" option.
A perl script called rsyncstats to summarize this format is
included in the rsync source code distribution.
timeout
The "timeout" option allows you to override the clients choice
for I/O timeout for this module. Using this option you can
ensure that rsync won’t wait on a dead client forever. The
timeout is specified in seconds. A value of zero means no time-
out and is the default. A good choice for anonymous rsync
servers may be 600 (giving a 10 minute timeout).
refuse options
The "refuse options" option allows you to specify a space-sepa-
rated list of rsync command line options that will be refused
by your rsync server. You may specify the full option name,
its one-letter abbreviation, or a wild-card string that matches
multiple options. For example, this would refuse --checksum
(-c) and all the options that start with "delete":
refuse options = c delete*
When an option is refused, the server prints an error message
and exits. To prevent all compression, you can use "dont com-
press = *" (see below) instead of "refuse options = compress"
to avoid returning an error to a client that requests compres-
sion.
dont compress
The "dont compress" option allows you to select filenames based
on wildcard patterns that should not be compressed during
transfer. Compression is expensive in terms of CPU usage so it
is usually good to not try to compress files that won’t com-
press well, such as already compressed files.
The "dont compress" option takes a space-separated list of
case-insensitive wildcard patterns. Any source filename match-
ing one of the patterns will not be compressed during transfer.
The default setting is
*.gz *.tgz *.zip *.z *.rpm *.deb *.iso *.bz2 *.tbz
AUTHENTICATION STRENGTH
The authentication protocol used in rsync is a 128 bit MD4 based chal-
lenge response system. Although I believe that no one has ever demon-
strated a brute-force break of this sort of system you should realize
that this is not a "military strength" authentication system. It
should be good enough for most purposes but if you want really top
quality security then I recommend that you run rsync over ssh.
Also note that the rsync server protocol does not currently provide
any encryption of the data that is transferred over the connection.
Only authentication is provided. Use ssh as the transport if you want
encryption.
Future versions of rsync may support SSL for better authentication and
encryption, but that is still being investigated.
RUNNING AN RSYNC SERVER OVER A REMOTE SHELL PROGRAM
If rsync is run with both the --daemon and --rsh (-e) options, it will
spawn an rsync daemon using a remote shell connection. Several con-
figuration options will not be available unless the remote user is
root (e.g. chroot, setuid/setgid, etc.). There is no need to config-
ure inetd or the services map to include the rsync server port if you
run an rsync server only via a remote shell program.
ADVANCED: To run an rsync server out of a single-use ssh key, use the
"command=COMMAND" syntax in the remote user’s authorized_keys entry,
where command would be
rsync --server --daemon .
NOTE: rsync’s argument parsing expects the trailing ".", so make sure
that it’s there. If you want to use an rsyncd.conf(5)-style configu-
ration file other than the default, you can added a --config option to
the command:
rsync --server --daemon --config=file .
Note that the "--server" here is the internal option that rsync uses
to run the remote version of rsync that it communicates with, and thus
you should not be using the --server option under normal circum-
stances.
EXAMPLES
A simple rsyncd.conf file that allow anonymous rsync to a ftp area at
/home/ftp would be:
[ftp]
path = /home/ftp
comment = ftp export area
A more sophisticated example would be:
uid = nobody
gid = nobody
use chroot = no
max connections = 4
syslog facility = local5
pid file = /var/run/rsyncd.pid
[ftp]
path = /var/ftp/pub
comment = whole ftp area (approx 6.1 GB)
[sambaftp]
path = /var/ftp/pub/samba
comment = Samba ftp area (approx 300 MB)
[rsyncftp]
path = /var/ftp/pub/rsync
comment = rsync ftp area (approx 6 MB)
[sambawww]
path = /public_html/samba
comment = Samba WWW pages (approx 240 MB)
[cvs]
path = /data/cvs
comment = CVS repository (requires authentication)
auth users = tridge, susan
secrets file = /etc/rsyncd.secrets
The /etc/rsyncd.secrets file would look something like this:
tridge:mypass
susan:herpass
FILES
/etc/rsyncd.conf or rsyncd.conf
SEE ALSO
rsync(1)
DIAGNOSTICS
BUGS
The rsync server does not send all types of error messages to the
client. this means a client may be mystified as to why a transfer
failed. The error will have been logged by syslog on the server.
Please report bugs! The rsync bug tracking system is online at
http://rsync.samba.org/
VERSION
This man page is current for version 2.x of rsync.
CREDITS
rsync is distributed under the GNU public license. See the file COPY-
ING for details.
The primary ftp site for rsync is ftp://rsync.samba.org/pub/rsync.
A WEB site is available at http://rsync.samba.org/
We would be delighted to hear from you if you like this program.
This program uses the zlib compression library written by Jean-loup
Gailly and Mark Adler.
THANKS
Thanks to Warren Stanley for his original idea and patch for the rsync
server. Thanks to Karsten Thygesen for his many suggestions and docu-
mentation!
AUTHOR
rsync was written by Andrew Tridgell and Paul Mackerras. They may be
contacted via email at tridge@samba.org and Paul.Macker-
ras@cs.anu.edu.au
30 Sep 2004 rsyncd.conf(5)
