rsyncd.conf - configuration file for rsync in daemon mode
The rsyncd.conf file is the runtime configuration file for rsync when run as an
The rsyncd.conf file controls authentication, access, logging and available
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 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. (If a hash occurs after anything other than leading
whitespace, it is considered a part of the line’s 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 significant in boolean values, but is preserved in string values.
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.
When run via inetd you should add a line like this to
and a single line something like this to /usr/local/etc/rsync/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.
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 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 starting the
- pid file
- This parameter tells the rsync daemon to write its process 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
- 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.
- 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.
After the global parameters 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] 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 single space, while leading or
trailing whitespace will be discarded. Also, the name cannot be
"global" as that exact name indicates that global parameters follow
As with GLOBAL PARAMETERS, you may use references to environment variables in
the values of parameters. See the GLOBAL PARAMETERS section for more details.
- 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.
- This parameter specifies the directory in the daemon’s filesystem
to make available in this module. You must specify this parameter for each
module in rsyncd.conf.
- You may base the path’s 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 user’s 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 shouldn’t 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 groups by name (see below).
- As an additional safety feature, you can specify a dot-dir in the
module’s "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 both "use chroot" and "daemon chroot" are false,
OR the inside-chroot path of "use chroot" 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) substitute leading slashes in absolute paths with
the module’s path (so that options such as --backup-dir,
--compare-dest, etc. interpret an absolute path as rooted in the
module’s "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 module’s chroot area, you
should protect them through your OS’s normal user/group or ACL
settings (to prevent the rsync module’s user from being able to
change them), and then hide them from the user’s 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 the "numeric ids" daemon parameter (see below).
- 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.
- daemon chroot
- This parameter specifies a path to which the daemon will chroot before
beginning communication with clients. Module paths (and any "use
chroot" settings) will then be related to this one. This lets you
choose if you want the whole daemon to be chrooted (with this setting),
just the transfers to be chrooted (with "use chroot"), or both.
Keep in mind that the "daemon chroot" area may need various
OS/lib/etc files installed to allow the daemon to function. By default the
daemon runs without any chrooting.
- numeric ids
- 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 disabled 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
you’ve 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 starting 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 with an inside-chroot path of "/",
OR if "daemon chroot" is on, 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 module’s path (as access-permissions
- 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 can’t try to create it.
- Note: rsync makes no attempt to verify that any pre-existing symlinks in
the module’s 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 symlink’s 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 symlinks.
- 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 leading slash and to remove
".." path elements that rsync believes will allow a symlink to
escape the module’s hierarchy. There are tricky ways to work around
this, though, so you had better trust your users if you choose this
combination of parameters.
- This specifies the name of the character set in which the module’s
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
support 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.
- log file
- When the "log file" parameter is set to a non-empty string, the
rsync daemon will log messages to the indicated file rather than using
syslog. This is particularly useful on systems (such as AIX) where
syslog() doesn’t 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
- 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 parameters of the daemon and all module settings. The
latter sets the daemon’s 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 facility 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 settings).
- syslog tag
- This parameter allows you to specify the syslog tag to use when logging
messages from the rsync daemon. The default is "rsyncd". 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
- For example, if you wanted each authenticated user’s name to be
included in the syslog tag, you could do something like this:
syslog tag = rsyncd.%RSYNC_USER_NAME%
- max verbosity
- This parameter allows you to control the maximum amount of verbose
information that you’ll 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 user’s 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 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
- 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
- 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 permissions on the daemon side allow them. The default is
for this parameter to be disabled.
- Helpful hint: you probably want to specify "refuse options =
delete" for a write-only module.
- 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 globally 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.
- 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 combination with the "gid" parameter this determines what
file permissions are available. The default when run by a super-user is to
switch to the system’s "nobody" user. The default for a
non-super-user is to not try to change the user. See also the
- 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
uid = %RSYNC_USER_NAME%
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 transfer’s user (see "uid").
The default when run by a super-user is to switch to your OS’s
"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).
- daemon uid
- This parameter specifies a uid under which the daemon will run. The daemon
usually runs as user root, and when this is left unset the user is left
unchanged. See also the "uid" parameter.
- daemon gid
- This parameter specifies a gid under which the daemon will run. The daemon
usually runs as group root, and when this is left unset, the group is left
unchanged. See also the "gid" parameter.
- 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 attributes of a file to be stored without
having to have the daemon actually running as root.
- 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 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 tampering 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" parameters, 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.
- 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 daemon.
- 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
description of how excluded files affect the daemon.
- exclude from
- This parameter specifies the name of a file on the daemon 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 permissions 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 permissions 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
- outgoing chmod
- This parameter allows you to specify a set of comma-separated chmod
strings that will affect the permissions 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 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 supply 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
- In addition to username matching, you can specify groupname matching via a
’@’ prefix. When using groupname 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 setting overrides the module’s "read
- 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 didn’t match an earlier group-matching
- If you need to specify a user or group name with a space in it, start your
list with a comma to indicate that the list should only be split on commas
(though leading and trailing whitespace will also be removed, and empty
entries are just ignored). For example:
auth users = , joe:deny, @Some Group:deny, admin:rw, @RO Group:ro
- 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 their user password or (when applicable) a group
password, 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
- secrets file
- This parameter specifies the name of a file that contains the
username:password and/or @groupname:password pairs used for authenticating
this module. This file is only consulted if the "auth users"
parameter is specified. 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 don’t
- The use of group-specific lines are only relevant when the module is being
authorized using a matching "@groupname" rule. When that
happens, the user can be authorized 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 /usr/local/etc/rsync/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 permissions 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 parameter was added
to accommodate rsync running on the Windows operating system.
- hosts allow
- This parameter allows you to specify a list of comma- and/or
whitespace-separated patterns that are matched against a connecting
client’s hostname and IP address. If none of the patterns match,
then the connection is rejected.
- Each pattern can be in one of five forms:
- 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.
- 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.
- an address/mask in the form ipaddr/maskaddr where ipaddr is the IP address
and maskaddr is the netmask in dotted decimal notation 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.
- a hostname pattern using wildcards. If the hostname 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
- 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
- Note IPv6 link-local addresses can have a scope in the address
- 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
- hosts deny
- This parameter allows you to specify a list of comma- and/or
whitespace-separated patterns that are matched against a connecting
clients hostname and IP address. If the pattern matches then the
connection is rejected. See the "hosts allow" parameter for more
- The default is no "hosts deny" parameter, which means all hosts
- reverse lookup
- Controls whether the daemon performs a reverse lookup on the
client’s 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 daemon will use the name
- 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 globally 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 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 disastrous 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
doesn’t 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"
- 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 embedded 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 numerical 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 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:
- %a the remote IP address (only available for a daemon)
- %b the number of bytes actually transferred
- %B the permission bits of the file (e.g. rwxrwxrwt)
- %c the total size of the block checksums received for the basis file (only
- %C the full-file checksum if it is known for the file. For older rsync
protocols/versions, the checksum was salted, and is thus not a useful
value (and is not displayed when that is the case). For the checksum to
output for a file, either the --checksum option must be in-effect
or the file must have been transferred without a salted checksum being
used. See the --checksum-choice option for a way to choose the
- %f the filename (long form on sender; no trailing "/")
- %G the gid of the file (decimal) or "DEFAULT"
- %h the remote host name (only available for a daemon)
- %i an itemized list of what is being updated
- %l the length of the file in bytes
- %L the string " -> SYMLINK", " => HARDLINK", or
"" (where SYMLINK or HARDLINK is a filename)
- %m the module name
- %M the last-modified time of the file
- %n the filename (short form; trailing "/" on dir)
- %o the operation, which is "send", "recv", or
"del." (the latter includes the trailing period)
- %p the process ID of this rsync session
- %P the module path
- %t the current date time
- %u the authenticated username or an empty string
- %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 talking with older rsync
versions. For instance, deleted files were only output as verbose messages
prior to rsync 2.6.4.
- This parameter allows you to override the clients choice for I/O timeout
for this module. Using this parameter 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 timeout and is the default. A good
choice for anonymous rsync daemons may be 600 (giving a 10 minute
- 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
"delete-*" -- that refuses all the delete modes without
- 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
- 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 won’t compress well, such as already
- 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) manpage
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
daemon’s stderr, which is typically discarded (though see
--no-detatch option for a way to see the stderr output, which can assist
- The following environment variables will be set, though some are specific
to the pre-xfer or the post-xfer environment:
- RSYNC_MODULE_NAME: The name of the module being accessed.
- RSYNC_MODULE_PATH: The path configured for the module.
- RSYNC_HOST_ADDR: The accessing host’s IP address.
- RSYNC_HOST_NAME: The accessing host’s name.
- RSYNC_USER_NAME: The accessing user’s name (empty if no
- RSYNC_PID: A unique number for this transfer.
- 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.
- RSYNC_ARG#: (pre-xfer only) The pre-request arguments 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.
- RSYNC_EXIT_STATUS: (post-xfer only) the server side’s 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 properly. 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
- RSYNC_RAW_STATUS: (post-xfer only) the raw exit value from
- Even though the commands can be associated with a particular module, they
are run using the permissions of the user that started the daemon (not the
module’s uid/gid setting) without any chroot restrictions.
There are currently two config directives available that allow a config file to
incorporate the contents of other files: &include
. Both allow a reference to either a file or a directory.
They differ in how segregated the file’s contents are considered to be.
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.
directive, on the other hand, treats the file’s
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
directive refers to a
directory, it will read in all the *.conf
(respectively) that are contained inside that directory (without any recursive
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:
would be the same as this set of directives:
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 worrying 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
), or globals that will affect other include files.
For example, this is a useful /usr/local/etc/rsync/rsyncd.conf file:
port = 873
log file = /var/log/rsync.log
pid file = /var/lock/rsync.lock
This would merge any /usr/local/etc/rsync/rsyncd.d/*.inc files (for global
values that should stay in effect), and then include any
/usr/local/etc/rsync/rsyncd.d/*.conf files (defining modules without any
The authentication protocol used in rsync is a 128 bit MD4 based challenge
response system. This is fairly weak protection, 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 authentication and
encryption, but that is still being investigated.
A simple rsyncd.conf file that allow anonymous rsync to a ftp area at /home/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
path = /var/ftp/./pub
comment = whole ftp area (approx 6.1 GB)
path = /var/ftp/./pub/samba
comment = Samba ftp area (approx 300 MB)
path = /var/ftp/./pub/rsync
comment = rsync ftp area (approx 6 MB)
path = /public_html/samba
comment = Samba WWW pages (approx 240 MB)
path = /data/cvs
comment = CVS repository (requires authentication)
auth users = tridge, susan
secrets file = /usr/local/etc/rsync/rsyncd.secrets
The /usr/local/etc/rsync/rsyncd.secrets file would look something like this:
/usr/local/etc/rsync/rsyncd.conf or rsyncd.conf
Please report bugs! The rsync bug tracking system is online at
This man page is current for version 3.1.3 of rsync.
rsync is distributed under the GNU General Public License. See the file COPYING
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
Thanks to Warren Stanley for his original idea and patch for the rsync daemon.
Thanks to Karsten Thygesen for his many suggestions and documentation!
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