rsyncd.conf(5)
rsyncd.conf(5) FILE FORMATS rsyncd.conf(5)
NAME
rsyncd.conf - configuration file for rsync in daemon mode
SYNOPSIS
rsyncd.conf
DESCRIPTION
The rsyncd.conf file is the runtime configuration file for
rsync when run as an rsync daemon.
The rsyncd.conf file controls authentication, access, log-
ging 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 represents either a comment, a module name or a parame-
ter.
Only the first equals sign in a parameter is significant.
Whitespace before or after the first equals sign is dis-
carded. Leading, trailing and internal whitespace in module
and parameter names is irrelevant. Leading and trailing whi-
tespace in a parameter value is discarded. Internal whi-
tespace within a parameter value is retained verbatim.
Any line beginning with a hash (#) is ignored, as are lines
containing only whitespace. (If a hash occurs after anything
other than leading whitespace, it is considered a part of
the lines content.)
Any line ending in a \ is continued on the next line in the
customary 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 signifi-
cant 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.
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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.
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 signal to tell it to reread its config file.
Note that you should not send the rsync daemon a HUP signal
to force it to reread the rsyncd.conf file. The file is
re-read on each client connection.
GLOBAL PARAMETERS
The first parameters in the file (before a [module] header)
are the global parameters. Rsync also allows for the use of
a [global] module name to indicate the start of one or more
global-parameter sections (the name must be lower case).
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.
You may use references to environment variables in the
values of parameters. String parameters will have %VAR%
references expanded as late as possible (when the string is
used in the program), allowing for the use of variables that
rsync sets at connection time, such as RSYNC_USER_NAME.
Non-string parameters (such as true/false settings) are
expanded when read from the config file. If a variable does
not exist in the environment, or if a sequence of characters
is not a valid reference (such as an un-paired percent
sign), the raw characters are passed through unchanged.
This helps with backward compatibility and safety (e.g.
expanding a non-existent %VAR% to an empty string in a path
could result in a very unsafe path). The safest way to
insert a literal % into a value is to use %%.
motd file
This parameter allows you to specify a message of the
day to display to clients on each connect. This usually
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contains site information and any legal notices. The
default is no motd file. This can be overridden by the
--dparam=motdfile=FILE command-line option when start-
ing the daemon.
pid file
This parameter tells the rsync daemon to write its pro-
cess ID to that file. If the file already exists, the
rsync daemon will abort rather than overwrite the file.
This can be overridden by the --dparam=pidfile=FILE
command-line option when starting the daemon.
port You can override the default port the daemon will
listen on by specifying this value (defaults to 873).
This is ignored if the daemon is being run by inetd,
and is superseded by the --port command-line option.
address
You can override the default IP address the daemon will
listen on by specifying this value. This is ignored if
the daemon is being run by inetd, and is superseded by
the --address command-line option.
socket options
This parameter 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. These settings can also be
specified via the --sockopts command-line option.
listen backlog
You can override the default backlog value when the
daemon listens for connections. It defaults to 5.
MODULE PARAMETERS
After the global parameters you should define a number of
modules, each module exports a directory tree as a symbolic
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name. Modules are exported by specifying a module name in
square brackets [module] followed by the parameters for that
module. The module name cannot contain a slash or a closing
square bracket. If the name contains whitespace, each
internal sequence of whitespace will be changed into a sin-
gle space, while leading or trailing whitespace will be dis-
carded. Also, the name cannot be global as that exact name
indicates that global parameters follow (see above).
As with GLOBAL PARAMETERS, you may use references to
environment variables in the values of parameters. See the
GLOBAL PARAMETERS section for more details.
comment
This parameter 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 This parameter specifies the directory in the daemons
filesystem to make available in this module. You must
specify this parameter for each module in rsyncd.conf.
You may base the paths value off of an environment
variable by surrounding the variable name with percent
signs. You can even reference a variable that is set
by rsync when the user connects. For example, this
would use the authorizing users name in the path:
path = /home/%RSYNC_USER_NAME%
It is fine if the path includes internal spaces -- they
will be retained verbatim (which means that you
shouldnt try to escape them). If your final directory
has a trailing space (and this is somehow not something
you wish to fix), append a trailing slash to the path
to avoid losing the trailing whitespace.
use chroot
If use chroot is true, the rsync daemon will chroot to
the path before starting the file transfer with the
client. This has the advantage of extra protection
against possible implementation 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 users and
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groups by name (see below).
As an additional safety feature, you can specify a
dot-dir in the modules path to indicate the point where
the chroot should occur. This allows rsync to run in a
chroot with a non-/ path for the top of the transfer
hierarchy. Doing this guards against unintended
library loading (since those absolute paths will not be
inside the transfer hierarchy unless you have used an
unwise pathname), and lets you setup libraries for the
chroot that are outside of the transfer. For example,
specifying /var/rsync/./module1 will chroot to the
/var/rsync directory and set the inside-chroot path to
/module1. If you had omitted the dot-dir, the chroot
would have used the whole path, and the inside-chroot
path would have been /.
When use chroot is false or the inside-chroot path is
not /, rsync will: (1) munge symlinks by default for
security reasons (see munge symlinks for a way to turn
this off, but only if you trust your users), (2) sub-
stitute leading slashes in absolute paths with the
modules path (so that options such as --backup-dir,
--compare-dest, etc. interpret an absolute path as
rooted in the modules path dir), and (3) trim .. path
elements from args if rsync believes they would escape
the module hierarchy. The default for use chroot is
true, and is the safer choice (especially if the module
is not read-only).
When this parameter is enabled, the numeric-ids option
will also default to being enabled (disabling name
lookups). See below for what a chroot needs in order
for name lookups to succeed.
If you copy library resources into the modules chroot
area, you should protect them through your OSs normal
user/group or ACL settings (to prevent the rsync
modules user from being able to change them), and then
hide them from the users view via exclude (see how in
the discussion of that parameter). At that point it
will be safe to enable the mapping of users and groups
by name using this numeric ids daemon parameter.
Note also that you are free to setup custom user/group
information in the chroot area that is different from
your normal system. For example, you could abbreviate
the list of users and groups.
numeric ids
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Enabling this parameter disables the mapping of users
and groups by name for the current daemon module. This
prevents the daemon from trying to load any
user/group-related files or libraries. This enabling
makes the transfer behave as if the client had passed
the --numeric-ids command-line option. By default,
this parameter is enabled for chroot modules and dis-
abled for non-chroot modules. Also keep in mind that
uid/gid preservation requires the module to be running
as root (see uid) or for fake super to be configured.
A chroot-enabled module should not have this parameter
enabled unless youve taken steps to ensure that the
module has the necessary resources it needs to
translate names, and that it is not possible for a user
to change those resources. That includes being the
code being able to call functions like getpwuid() ,
getgrgid() , getpwname() , and getgrnam() ). You
should test what libraries and config files are
required for your OS and get those setup before start-
ing to test name mapping in rsync.
munge symlinks
This parameter tells rsync to modify all symlinks in
the same way as the (non-daemon-affecting)
--munge-links command-line option (using a method
described below). This should help protect your files
from user trickery when your daemon module is writable.
The default is disabled when use chroot is on and the
inside-chroot path is /, otherwise it is enabled.
If you disable this parameter on a daemon that is not
read-only, there are tricks that a user can play with
uploaded symlinks to access daemon-excluded items (if
your module has any), and, if use chroot is off, rsync
can even be tricked into showing or changing data that
is outside the modules path (as access-permissions
allow).
The way rsync disables the use of symlinks is to prefix
each one with the string /rsyncd-munged/. This
prevents the links from being used as long as that
directory does not exist. When this parameter is
enabled, rsync will refuse to run if that path is a
directory or a symlink to a directory. When using the
munge symlinks parameter in a chroot area that has an
inside-chroot path of /, you should add /rsyncd-munged/
to the exclude setting for the module so that a user
cant try to create it.
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Note: rsync makes no attempt to verify that any
pre-existing symlinks in the modules hierarchy are as
safe as you want them to be (unless, of course, it just
copied in the whole hierarchy). If you setup an rsync
daemon on a new area or locally add symlinks, you can
manually protect your symlinks from being abused by
prefixing /rsyncd-munged/ to the start of every
symlinks value. There is a perl script in the support
directory of the source code named munge-symlinks that
can be used to add or remove this prefix from your sym-
links.
When this parameter is disabled on a writable module
and use chroot is off (or the inside-chroot path is not
/), incoming symlinks will be modified to drop a lead-
ing slash and to remove .. path elements that rsync
believes will allow a symlink to escape the modules
hierarchy. There are tricky ways to work around this,
though, so you had better trust your users if you
choose this combination of parameters.
charset
This specifies the name of the character set in which
the modules filenames are stored. If the client uses
an --iconv option, the daemon will use the value of the
charset parameter regardless of the character set the
client actually passed. This allows the daemon to sup-
port charset conversion in a chroot module without
extra files in the chroot area, and also ensures that
name-translation is done in a consistent manner. If
the charset parameter is not set, the --iconv option is
refused, just as if iconv had been specified via refuse
options.
If you wish to force users to always use --iconv for a
particular module, add no-iconv to the refuse options
parameter. Keep in mind that this will restrict access
to your module to very new rsync clients.
max connections
This parameter 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. A negative value
disables the module. See also the lock file parameter.
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log file
When the log file parameter is set to a non-empty
string, the rsync daemon will log messages to the indi-
cated file rather than using syslog. This is particu-
larly useful on systems (such as AIX) where syslog()
doesnt work for chrooted programs. The file is opened
before chroot() is called, allowing it to be placed
outside the transfer. If this value is set on a
per-module basis instead of globally, the global log
will still contain any authorization failures or
config-file error messages.
If the daemon fails to open the specified file, it will
fall back to using syslog and output an error about the
failure. (Note that the failure to open the specified
log file used to be a fatal error.)
This setting can be overridden by using the
--log-file=FILE or --dparam=logfile=FILE command-line
options. The former overrides all the log-file parame-
ters of the daemon and all module settings. The latter
sets the daemons log file and the default for all the
modules, which still allows modules to override the
default setting.
syslog facility
This parameter allows you to specify the syslog facil-
ity name to use when logging messages from the rsync
daemon. 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. This setting has no effect if the log file
setting is a non-empty string (either set in the
per-modules settings, or inherited from the global set-
tings).
max verbosity
This parameter allows you to control the maximum amount
of verbose information that youll allow the daemon to
generate (since the information goes into the log
file). The default is 1, which allows the client to
request one level of verbosity.
This also affects the users ability to request higher
levels of --info and --debug logging. If the max value
is 2, then no info and/or debug value that is higher
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than what would be set by -vv will be honored by the
daemon in its logging. To see how high of a verbosity
level you need to accept for a particular info/debug
level, refer to rsync --info=help and rsync
--debug=help. For instance, it takes max-verbosity 4
to be able to output debug TIME2 and FLIST3.
lock file
This parameter specifies the file to use to support the
max connections parameter. The rsync daemon 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
This parameter 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
daemon side allow them. The default is for all modules
to be read only.
Note that auth users can override this setting on a
per-user basis.
write only
This parameter 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 permis-
sions on the daemon side allow them. The default is
for this parameter to be disabled.
list This parameter determines whether this module is listed
when the client asks for a listing of available
modules. In addition, if this is false, the daemon
will pretend the module does not exist when a client
denied by hosts allow or hosts deny attempts to access
it. Realize that if reverse lookup is disabled glo-
bally but enabled for the module, the resulting reverse
lookup to a potentially client-controlled DNS server
may still reveal to the client that it hit an existing
module. The default is for modules to be listable.
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uid This parameter 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 combina-
tion with the gid parameter this determines what file
permissions are available. The default when run by a
super-user is to switch to the systems nobody user.
The default for a non-super-user is to not try to
change the user. See also the gid parameter.
The RSYNC_USER_NAME environment variable may be used to
request that rsync run as the authorizing user. For
example, if you want a rsync to run as the same user
that was received for the rsync authentication, this
setup is useful:
uid = %RSYNC_USER_NAME%
gid = *
gid This parameter specifies one or more group names/IDs
that will be used when accessing the module. The first
one will be the default group, and any extra ones be
set as supplemental groups. You may also specify a *
as the first gid in the list, which will be replaced by
all the normal groups for the transfers user (see uid).
The default when run by a super-user is to switch to
your OSs nobody (or perhaps nogroup) group with no
other supplementary groups. The default for a
non-super-user is to not change any group attributes
(and indeed, your OS may not allow a non-super-user to
try to change their group settings).
fake super
Setting fake super = yes for a module causes the daemon
side to behave as if the --fake-super command-line
option had been specified. This allows the full attri-
butes of a file to be stored without having to have the
daemon actually running as root.
filter
The daemon has its own filter chain that determines
what files it will let the client access. This chain
is not sent to the client and is independent of any
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filters the client may have specified. Files excluded
by the daemon filter chain (daemon-excluded files) are
treated as non-existent if the client tries to pull
them, are skipped with an error message if the client
tries to push them (triggering exit code 23), and are
never deleted from the module. You can use daemon
filters to prevent clients from downloading or tamper-
ing with private administrative files, such as files
you may add to support uid/gid name translations.
The daemon filter chain is built from the filter,
include from, include, exclude from, and exclude param-
eters, in that order of priority. Anchored patterns
are anchored at the root of the module. To prevent
access to an entire subtree, for example, /secret, you
must exclude everything in the subtree; the easiest way
to do this is with a triple-star pattern like
/secret/***.
The filter parameter takes a space-separated list of
daemon filter rules, though it is smart enough to know
not to split a token at an internal space in a rule
(e.g. - /foo - /bar is parsed as two rules). You may
specify one or more merge-file rules using the normal
syntax. Only one filter parameter can apply to a given
module in the config file, so put all the rules you
want in a single parameter. Note that per-directory
merge-file rules do not provide as much protection as
global rules, but they can be used to make --delete
work better during a client download operation if the
per-dir merge files are included in the transfer and
the client requests that they be used.
exclude
This parameter takes a space-separated list of daemon
exclude patterns. As with the client --exclude option,
patterns can be qualified with - or + to explicitly
indicate exclude/include. Only one exclude parameter
can apply to a given module. See the filter parameter
for a description of how excluded files affect the dae-
mon.
include
Use an include to override the effects of the exclude
parameter. Only one include parameter can apply to a
given module. See the filter parameter for a descrip-
tion of how excluded files affect the daemon.
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rsyncd.conf(5) FILE FORMATS rsyncd.conf(5)
exclude from
This parameter specifies the name of a file on the dae-
mon that contains daemon exclude patterns, one per
line. Only one exclude from parameter can apply to a
given module; if you have multiple exclude-from files,
you can specify them as a merge file in the filter
parameter. See the filter parameter for a description
of how excluded files affect the daemon.
include from
Analogue of exclude from for a file of daemon include
patterns. Only one include from parameter can apply to
a given module. See the filter parameter for a
description of how excluded files affect the daemon.
incoming chmod
This parameter allows you to specify a set of
comma-separated chmod strings that will affect the per-
missions of all incoming files (files that are being
received by the daemon). These changes happen after
all other permission calculations, and this will even
override destination-default and/or existing permis-
sions when the client does not specify --perms. See
the description of the --chmod rsync option and the
chmod(1) manpage for information on the format of this
string.
outgoing chmod
This parameter allows you to specify a set of
comma-separated chmod strings that will affect the per-
missions of all outgoing files (files that are being
sent out from the daemon). These changes happen first,
making the sent permissions appear to be different than
those stored in the filesystem itself. For instance,
you could disable group write permissions on the server
while having it appear to be on to the clients. See
the description of the --chmod rsync option and the
chmod(1) manpage for information on the format of this
string.
auth users
This parameter specifies a comma and/or space-separated
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list of authorization rules. In its simplest form, you
list the usernames that will be allowed to connect to
this module. The usernames do not need to exist on the
local system. The rules may contain shell wildcard
characters that will be matched against the username
provided by the client for authentication. If auth
users is set then the client will be challenged to sup-
ply a username and password to connect to the module. A
challenge response authentication protocol is used for
this exchange. The plain text usernames and passwords
are stored in the file specified by the secrets file
parameter. The default is for all users to be able to
connect without a password (this is called anonymous
rsync).
In addition to username matching, you can specify
groupname matching via a @ prefix. When using group-
name matching, the authenticating username must be a
real user on the system, or it will be assumed to be a
member of no groups. For example, specifying @rsync
will match the authenticating user if the named user is
a member of the rsync group.
Finally, options may be specified after a colon (:).
The options allow you to deny a user or a group, set
the access to ro (read-only), or set the access to rw
(read/write). Setting an auth-rule-specific ro/rw set-
ting overrides the modules read only setting.
Be sure to put the rules in the order you want them to
be matched, because the checking stops at the first
matching user or group, and that is the only auth that
is checked. For example:
auth users = joe:deny @guest:deny admin:rw @rsync:ro susan joe sam
In the above rule, user joe will be denied access no
matter what. Any user that is in the group guest is
also denied access. The user admin gets access in
read/write mode, but only if the admin user is not in
group guest (because the admin user-matching rule would
never be reached if the user is in group guest). Any
other user who is in group rsync will get read-only
access. Finally, users susan, joe, and sam get the
ro/rw setting of the module, but only if the user didnt
match an earlier group-matching rule.
See the description of the secrets file for how you can
have per-user passwords as well as per-group passwords.
It also explains how a user can authenticate using
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rsyncd.conf(5) FILE FORMATS rsyncd.conf(5)
their user password or (when applicable) a group pass-
word, depending on what rule is being authenticated.
See also the section entitled USING RSYNC-DAEMON
FEATURES VIA A REMOTE SHELL CONNECTION 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 daemon.
secrets file
This parameter specifies the name of a file that con-
tains the username:password and/or @groupname:password
pairs used for authenticating this module. This file is
only consulted if the auth users parameter is speci-
fied. The file is line-based and contains one
name:password pair per line. Any line has a hash (#)
as the very first character on the line 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 dont work.
The use of group-specific lines are only relevant when
the module is being authorized using a matching @group-
name rule. When that happens, the user can be author-
ized via either their username:password line or the
@groupname:password line for the group that triggered
the authentication.
It is up to you what kind of password entries you want
to include, either users, groups, or both. The use of
group rules in auth users does not require that you
specify a group password if you do not want to use
shared passwords.
There is no default for the secrets file parameter, you
must choose a name (such as /etc/rsyncd.secrets). The
file must normally not be readable by other; see strict
modes. If the file is not found or is rejected, no
logins for a user auth module will be possible.
strict modes
This parameter 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 read-
able by any user ID other than the one that the rsync
daemon is running under. If strict modes is false, the
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check is not performed. The default is true. This
parameter was added to accommodate rsync running on the
Windows operating system.
hosts allow
This parameter allows you to specify a list of patterns
that are matched against a connecting clients hostname
and IP address. If none of the patterns match then the
connection 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 machines 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 net-
mask in dotted decimal notation for IPv4, or simi-
lar 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 pattern using wildcards. If the host-
name of the connecting IP (as determined by a
reverse lookup) matches the wildcarded name (using
the same rules as normal unix filename matching),
the client is allowed in. This only works if
reverse lookup is enabled (the default).
o a hostname. A plain hostname is matched against
the reverse DNS of the connecting IP (if reverse
lookup is enabled), and/or the IP of the given
hostname is matched against the connecting IP (if
forward lookup is enabled, as it is by default).
Any match will be allowed in.
Note IPv6 link-local addresses can have a scope in the
address specification:
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fe80::1%link1
fe80::%link1/64
fe80::%link1/ffff:ffff:ffff:ffff::
You can also combine hosts allow with a separate hosts
deny parameter. If both parameters are specified then
the hosts allow parameter is checked first and a match
results in the client being able to connect. The hosts
deny parameter 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 parameter, which means
all hosts can connect.
hosts deny
This parameter allows you to specify a list of patterns
that are matched against a connecting clients hostname
and IP address. If the pattern matches then the connec-
tion is rejected. See the hosts allow parameter for
more information.
The default is no hosts deny parameter, which means all
hosts can connect.
reverse lookup
Controls whether the daemon performs a reverse lookup
on the clients IP address to determine its hostname,
which is used for hosts allow/hosts deny checks and the
%h log escape. This is enabled by default, but you may
wish to disable it to save time if you know the lookup
will not return a useful result, in which case the dae-
mon will use the name UNDETERMINED instead.
If this parameter is enabled globally (even by
default), rsync performs the lookup as soon as a client
connects, so disabling it for a module will not avoid
the lookup. Thus, you probably want to disable it glo-
bally and then enable it for modules that need the
information.
forward lookup
Controls whether the daemon performs a forward lookup
on any hostname specified in an hosts allow/deny
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setting. By default this is enabled, allowing the use
of an explicit hostname that would not be returned by
reverse DNS of the connecting IP.
ignore errors
This parameter tells rsyncd to ignore I/O errors on the
daemon 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 disas-
trous 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 parameter to turn off
this behavior.
ignore nonreadable
This tells the rsync daemon 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 doesnt want
those files to be seen at all.
transfer logging
This parameter enables per-file logging of downloads
and uploads in a format somewhat similar to that used
by ftp daemons. The daemon always logs the transfer at
the end, so if a transfer is aborted, no mention will
be made in the log file.
If you want to customize the log lines, see the log
format parameter.
log format
This parameter allows you to specify the format used
for logging file transfers when transfer logging is
enabled. The format is a text string containing embed-
ded single-character escape sequences prefixed with a
percent (%) character. An optional numeric field width
may also be specified between the percent and the
escape letter (e.g. %-50n %8l %07p). In addition, one
or more apostrophes may be specified prior to a numeri-
cal escape to indicate that the numerical value should
be made more human-readable. The 3 supported levels
are the same as for the --human-readable command-line
option, though the default is for human-readability to
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be off. Each added apostrophe increases the level
(e.g. %''l %'b %f).
The default log format is %o %h [%a] %m (%u) %f %l, and
a %t [%p] is always prefixed when using the log file
parameter. (A perl script that will summarize this
default log format is included in the rsync source code
distribution in the support subdirectory: rsyncstats.)
The single-character escapes that are understood are as
follows:
o %a the remote IP address (only available for a
daemon)
o %b the number of bytes actually transferred
o %B the permission bits of the file (e.g.
rwxrwxrwt)
o %c the total size of the block checksums received
for the basis file (only when sending)
o %C the full-file MD5 checksum if --checksum is
enabled or a file was transferred (only for proto-
col 30 or above).
o %f the filename (long form on sender; no trailing
/)
o %G the gid of the file (decimal) or DEFAULT
o %h the remote host name (only available for a dae-
mon)
o %i an itemized list of what is being updated
o %l the length of the file in bytes
o %L the string -> SYMLINK, => HARDLINK, or
(where SYMLINK or HARDLINK is a filename)
o %m the module name
o %M the last-modified time of the file
o %n the filename (short form; trailing / on dir)
o %o the operation, which is send, recv, or del.
(the latter includes the trailing period)
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o %p the process ID of this rsync session
o %P the module path
o %t the current date time
o %u the authenticated username or an empty string
o %U the uid of the file (decimal)
For a list of what the characters mean that are output
by %i, see the --itemize-changes option in the rsync
manpage.
Note that some of the logged output changes when talk-
ing with older rsync versions. For instance, deleted
files were only output as verbose messages prior to
rsync 2.6.4.
timeout
This parameter allows you to override the clients
choice for I/O timeout for this module. Using this
parameter you can ensure that rsync wont wait on a dead
client forever. The timeout is specified in seconds. A
value of zero means no timeout and is the default. A
good choice for anonymous rsync daemons may be 600
(giving a 10 minute timeout).
refuse options
This parameter allows you to specify a space-separated
list of rsync command line options that will be refused
by your rsync daemon. 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 various
delete options:
refuse options = c delete
The reason the above refuses all delete options is that
the options imply --delete, and implied options are
refused just like explicit options. As an additional
safety feature, the refusal of delete also refuses
remove-source-files when the daemon is the sender; if
you want the latter without the former, instead refuse
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delete-* -- that refuses all the delete modes without
affecting --remove-source-files.
When an option is refused, the daemon prints an error
message and exits. To prevent all compression when
serving files, you can use dont compress = * (see
below) instead of refuse options = compress to avoid
returning an error to a client that requests compres-
sion.
dont compress
This parameter allows you to select filenames based on
wildcard patterns that should not be compressed when
pulling files from the daemon (no analogous parameter
exists to govern the pushing of files to a daemon).
Compression is expensive in terms of CPU usage, so it
is usually good to not try to compress files that wont
compress well, such as already compressed files.
The dont compress parameter takes a space-separated
list of case-insensitive wildcard patterns. Any source
filename matching one of the patterns will not be
compressed during transfer.
See the --skip-compress parameter in the rsync(1) man-
page for the list of file suffixes that are not
compressed by default. Specifying a value for the dont
compress parameter changes the default when the daemon
is the sender.
pre-xfer exec, post-xfer exec
You may specify a command to be run before and/or after
the transfer. If the pre-xfer exec command fails, the
transfer is aborted before it begins. Any output from
the script on stdout (up to several KB) will be
displayed to the user when aborting, but is NOT
displayed if the script returns success. Any output
from the script on stderr goes to the daemons stderr,
which is typically discarded (though see --no-detatch
option for a way to see the stderr output, which can
assist with debugging).
The following environment variables will be set, though
some are specific to the pre-xfer or the post-xfer
environment:
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o RSYNC_MODULE_NAME: The name of the module being
accessed.
o RSYNC_MODULE_PATH: The path configured for the
module.
o RSYNC_HOST_ADDR: The accessing hosts IP address.
o RSYNC_HOST_NAME: The accessing hosts name.
o RSYNC_USER_NAME: The accessing users name (empty
if no user).
o RSYNC_PID: A unique number for this transfer.
o RSYNC_REQUEST: (pre-xfer only) The module/path
info specified by the user. Note that the user
can specify multiple source files, so the request
can be something like mod/path1 mod/path2, etc.
o RSYNC_ARG#: (pre-xfer only) The pre-request argu-
ments are set in these numbered values. RSYNC_ARG0
is always rsyncd, followed by the options that
were used in RSYNC_ARG1, and so on. There will be
a value of . indicating that the options are done
and the path args are beginning -- these contain
similar information to RSYNC_REQUEST, but with
values separated and the module name stripped off.
o RSYNC_EXIT_STATUS: (post-xfer only) the server
sides exit value. This will be 0 for a successful
run, a positive value for an error that the server
generated, or a -1 if rsync failed to exit prop-
erly. Note that an error that occurs on the
client side does not currently get sent to the
server side, so this is not the final exit status
for the whole transfer.
o RSYNC_RAW_STATUS: (post-xfer only) the raw exit
value from waitpid() .
Even though the commands can be associated with a par-
ticular module, they are run using the permissions of
the user that started the daemon (not the modules
uid/gid setting) without any chroot restrictions.
CONFIG DIRECTIVES
There are currently two config directives available that
allow a config file to incorporate the contents of other
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files: &include and &merge. Both allow a reference to
either a file or a directory. They differ in how segregated
the files contents are considered to be.
The &include directive treats each file as more distinct,
with each one inheriting the defaults of the parent file,
starting the parameter parsing as globals/defaults, and
leaving the defaults unchanged for the parsing of the rest
of the parent file.
The &merge directive, on the other hand, treats the files
contents as if it were simply inserted in place of the
directive, and thus it can set parameters in a module
started in another file, can affect the defaults for other
files, etc.
When an &include or &merge directive refers to a directory,
it will read in all the *.conf or *.inc files (respectively)
that are contained inside that directory (without any recur-
sive scanning), with the files sorted into alpha order. So,
if you have a directory named rsyncd.d with the files
foo.conf, bar.conf, and baz.conf inside it, this directive:
&include /path/rsyncd.d
would be the same as this set of directives:
&include /path/rsyncd.d/bar.conf
&include /path/rsyncd.d/baz.conf
&include /path/rsyncd.d/foo.conf
except that it adjusts as files are added and removed from
the directory.
The advantage of the &include directive is that you can
define one or more modules in a separate file without worry-
ing about unintended side-effects between the self-contained
module files.
The advantage of the &merge directive is that you can load
config snippets that can be included into multiple module
definitions, and you can also set global values that will
affect connections (such as motd file), or globals that will
affect other include files.
For example, this is a useful /etc/rsyncd.conf file:
port = 873
log file = /var/log/rsync.log
pid file = /var/lock/rsync.lock
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&merge /etc/rsyncd.d
&include /etc/rsyncd.d
This would merge any /etc/rsyncd.d/*.inc files (for global
values that should stay in effect), and then include any
/etc/rsyncd.d/*.conf files (defining modules without any
global-value cross-talk).
AUTHENTICATION STRENGTH
The authentication protocol used in rsync is a 128 bit MD4
based challenge response system. This is fairly weak protec-
tion, though (with at least one brute-force hash-finding
algorithm publicly available), so if you want really
top-quality security, then I recommend that you run rsync
over ssh. (Yes, a future version of rsync will switch over
to a stronger hashing method.)
Also note that the rsync daemon 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 authen-
tication and encryption, but that is still being investi-
gated.
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 = yes
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
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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
Please report bugs! The rsync bug tracking system is online
at http://rsync.samba.org/
VERSION
This man page is current for version 3.1.2 of rsync.
CREDITS
rsync is distributed under the GNU General Public License.
See the file COPYING 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 pro-
gram.
This program uses the zlib compression library written by
Jean-loup Gailly and Mark Adler.
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THANKS
Thanks to Warren Stanley for his original idea and patch for
the rsync daemon. Thanks to Karsten Thygesen for his many
suggestions and documentation!
AUTHOR
rsync was written by Andrew Tridgell and Paul Mackerras.
Many people have later contributed to it.
Mailing lists for support and development are available at
http://lists.samba.org
Last change: 21 Dec 2015 25
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