RSYNC Switches with details

NAME

rsync - faster, flexible replacement for rcp  

SYNOPSIS

rsync [OPTION]... SRC [SRC]... [USER@]HOST:DEST
rsync [OPTION]... [USER@]HOST:SRC DEST
rsync [OPTION]... SRC [SRC]... DEST
rsync [OPTION]... [USER@]HOST::SRC [DEST]
rsync [OPTION]... SRC [SRC]... [USER@]HOST::DEST
rsync [OPTION]... rsync://[USER@]HOST[:PORT]/SRC [DEST]
 

DESCRIPTION

rsync is a program that behaves in much the same way that rcp does, but has many more options and uses the rsync remote-update protocol to greatly speedup file transfers when the destination file already exists. The rsync remote-update protocol allows rsync to transfer just the differences between two sets of files across the network link, using an efficient checksum-search algorithm described in the technical report that accompanies this package.
Some of the additional features of rsync are:

• support for copying links, devices, owners, groups and permissions
• exclude and exclude-from options similar to GNU tar
• a CVS exclude mode for ignoring the same files that CVS would ignore
• can use any transparent remote shell, including rsh or ssh
• does not require root privileges
• pipelining of file transfers to minimize latency costs
• support for anonymous or authenticated rsync servers (ideal for mirroring)

 

GENERAL

There are six different ways of using rsync. They are:

• for copying local files. This is invoked when neither source nor destination path contains a : separator
• for copying from the local machine to a remote machine using a remote shell program as the transport (such as rsh or ssh). This is invoked when the destination path contains a single : separator.
• for copying from a remote machine to the local machine using a remote shell program. This is invoked when the source contains a : separator.
• for copying from a remote rsync server to the local machine. This is invoked when the source path contains a :: separator or a rsync:// URL.
• for copying from the local machine to a remote rsync server. This is invoked when the destination path contains a :: separator.
• for listing files on a remote machine. This is done the same way as rsync transfers except that you leave off the local destination.

Note that in all cases (other than listing) at least one of the source and destination paths must be local.  

SETUP

See the file README for installation instructions. Once installed you can use rsync to any machine that you can use rsh to. rsync uses rsh for its communications, unless both the source and destination are local.
You can also specify an alternative to rsh, by either using the -e command line option, or by setting the RSYNC_RSH environment variable.
One common substitute is to use ssh, which offers a high degree of security.
Note that rsync must be installed on both the source and destination machines.
 

USAGE

You use rsync in the same way you use rcp. You must specify a source and a destination, one of which may be remote. Perhaps the best way to explain the syntax is some examples:

rsync *.c foo:src/

this would transfer all files matching the pattern *.c from the current directory to the directory src on the machine foo. If any of the files already exist on the remote system then the rsync remote-update protocol is used to update the file by sending only the differences. See the tech report for details.

rsync -avz foo:src/bar /data/tmp

this would recursively transfer all files from the directory src/bar on the machine foo into the /data/tmp/bar directory on the local machine. The files are transferred in "archive" mode, which ensures that symbolic links, devices, attributes, permissions, ownerships etc are preserved in the transfer. Additionally, compression will be used to reduce the size of data portions of the transfer.

rsync -avz foo:src/bar/ /data/tmp

a trailing slash on the source changes this behavior to transfer all files from the directory src/bar on the machine foo into the /data/tmp/. A trailing / on a source name means "copy the contents of this directory". Without a trailing slash it means "copy the directory". This difference becomes particularly important when using the --delete option.
You can also use rsync in local-only mode, where both the source and destination don't have a ':' in the name. In this case it behaves like an improved copy command.

rsync somehost.mydomain.com::

this would list all the anonymous rsync modules available on the host somehost.mydomain.com. (See the following section for more details.)
 

CONNECTING TO AN RSYNC SERVER

It is also possible to use rsync without using rsh or ssh as the transport. In this case you will connect to a remote rsync server running on TCP port 873. You may establish the connetcion via a web proxy by setting the environment variable RSYNC_PROXY to a hostname:port pair pointing to your web proxy. Note that your web proxy must allow proxying to port 873, this must be configured in your proxy servers ruleset.
Using rsync in this way is the same as using it with rsh or ssh except that:

you use a double colon :: instead of a single colon to separate the hostname from the path.

the remote server may print a message of the day when you connect.

if you specify no path name on the remote server then the list of accessible paths on the server will be shown.

if you specify no local destination then a listing of the specified files on the remote server is provided.

Some paths on the remote server may require authentication. If so then you will receive a password prompt when you connect. You can avoid the password prompt by setting the environment variable RSYNC_PASSWORD to the password you want to use or using the --password-file option. This may be useful when scripting rsync.
WARNING: On some systems environment variables are visible to all users. On those systems using --password-file is recommended.
 

RUNNING AN RSYNC SERVER

An rsync server is configured using a config file which by default is called /etc/rsyncd.conf. Please see the rsyncd.conf(5) man page for more information.  

EXAMPLES

Here are some examples of how I use rsync. To backup my wife's home directory, which consists of large MS Word files and mail folders, I use a cron job that runs

rsync -Cavz . arvidsjaur:backup

each night over a PPP link to a duplicate directory on my machine "arvidsjaur".
To synchronize my samba source trees I use the following Makefile targets:

get: rsync -avuzb --exclude '*~' samba:samba/ . put: rsync -Cavuzb . samba:samba/ sync: get put

this allows me to sync with a CVS directory at the other end of the link. I then do cvs operations on the remote machine, which saves a lot of time as the remote cvs protocol isn't very efficient.
I mirror a directory between my "old" and "new" ftp sites with the command

rsync -az -e ssh --delete ~ftp/pub/samba/ nimbus:"~ftp/pub/tridge/samba"

this is launched from cron every few hours.
 

OPTIONS SUMMARY

Here is a short summary of the options available in rsync. Please refer to the detailed description below for a complete description.

 


 -v, --verbose               increase verbosity

 -q, --quiet                 decrease verbosity

 -c, --checksum              always checksum

 -a, --archive               archive mode

 -r, --recursive             recurse into directories

 -R, --relative              use relative path names

 -b, --backup                make backups (default ~ suffix)

     --backup-dir=DIR        put backups in the specified directory

     --suffix=SUFFIX         override backup suffix

 -u, --update                update only (don't overwrite newer files)

 -l, --links                 preserve soft links

 -L, --copy-links            treat soft links like regular files

     --copy-unsafe-links     copy links outside the source tree

     --safe-links            ignore links outside the destination tree

 -H, --hard-links            preserve hard links

 -p, --perms                 preserve permissions

 -o, --owner                 preserve owner (root only)

 -g, --group                 preserve group

 -D, --devices               preserve devices (root only)

 -t, --times                 preserve times

 -S, --sparse                handle sparse files efficiently

 -n, --dry-run               show what would have been transferred

 -W, --whole-file            copy whole files, no incremental checks

 -x, --one-file-system       don't cross filesystem boundaries

 -B, --block-size=SIZE       checksum blocking size (default 700)

 -e, --rsh=COMMAND           specify rsh replacement

     --rsync-path=PATH       specify path to rsync on the remote machine

 -C, --cvs-exclude           auto ignore files in the same way CVS does

     --existing              only update files that already exist

     --delete                delete files that don't exist on the sending side

     --delete-excluded       also delete excluded files on the receiving side

     --delete-after          delete after transferring, not before

     --max-delete=NUM        don't delete more than NUM files

     --partial               keep partially transferred files

     --force                 force deletion of directories even if not empty

     --numeric-ids           don't map uid/gid values by user/group name

     --timeout=TIME          set IO timeout in seconds

 -I, --ignore-times          don't exclude files that match length and time

     --size-only             only use file size when determining if a file should be transferred

 -T  --temp-dir=DIR          create temporary files in directory DIR

     --compare-dest=DIR      also compare destination files relative to DIR

 -P                          equivalent to --partial --progress

 -z, --compress              compress file data

     --exclude=PATTERN       exclude files matching PATTERN

     --exclude-from=FILE     exclude patterns listed in FILE

     --include=PATTERN       don't exclude files matching PATTERN

     --include-from=FILE     don't exclude patterns listed in FILE

     --version               print version number

     --daemon                run as a rsync daemon

     --address               bind to the specified address

     --config=FILE           specify alternate rsyncd.conf file

     --port=PORT             specify alternate rsyncd port number

     --stats                 give some file transfer stats

     --progress              show progress during transfer

     --log-format=FORMAT     log file transfers using specified format

     --password-file=FILE    get password from FILE

 -h, --help                  show this help screen

 

OPTIONS

rsync uses the GNU long options package. Many of the command line options have two variants, one short and one long. These are shown below, separated by commas. Some options only have a long variant. The '=' for options that take a parameter is optional; whitespace can be used instead.

-h, --help

Print a short help page describing the options available in rsync

--version

print the rsync version number and exit

-v, --verbose

This option increases the amount of information you are given during the transfer. By default, rsync works silently. A single -v will give you information about what files are being transferred and a brief summary at the end. Two -v flags will give you information on what files are being skipped and slightly more information at the end. More than two -v flags should only be used if you are debugging rsync.

-q, --quiet

This option decreases the amount of information you are given during the transfer, notably suppressing information messages from the remote server. This flag is useful when invoking rsync from cron.

-I, --ignore-times

Normally rsync will skip any files that are already the same length and have the same time-stamp. This option turns off this behavior.

--size-only

Normally rsync will skip any files that are already the same length and have the same time-stamp. With the --size-only option files will be skipped if they have the same size, regardless of timestamp. This is useful when starting to use rsync after using another mirroring system which may not preserve timestamps exactly.

-c, --checksum

This forces the sender to checksum all files using a 128-bit MD4 checksum before transfer. The checksum is then explicitly checked on the receiver and any files of the same name which already exist and have the same checksum and size on the receiver are skipped. This option can be quite slow.

-a, --archive

This is equivalent to -rlptgoD. It is a quick way of saying you want recursion and want to preserve everything.

-r, --recursive

This tells rsync to copy directories recursively. If you don't specify this then rsync won't copy directories at all.

-R, --relative

Use relative paths. This means that the full path names specified on the command line are sent to the server rather than just the last parts of the filenames. This is particularly useful when you want to send several different directories at the same time. For example, if you used the command

   rsync foo/bar/foo.c remote:/tmp/

then this would create a file called foo.c in /tmp/ on the remote machine. If instead you used

   rsync -R foo/bar/foo.c remote:/tmp/

then a file called /tmp/foo/bar/foo.c would be created on the remote machine. The full path name is preserved.

-b, --backup

With this option preexisting destination files are renamed with a ~ extension as each file is transferred. You can control the backup suffix using the --suffix option.

--backup-dir=DIR

In combination with the --backup option, this tells rsync to store all backups in the specified directory. This is very useful for incremental backups.

--suffix=SUFFIX

This option allows you to override the default backup suffix used with the -b option. The default is a ~.

-u, --update

This forces rsync to skip any files for which the destination file already exists and has a date later than the source file.

-l, --links

This tells rsync to recreate symbolic links on the remote system to be the same as the local system. Without this option, all symbolic links are skipped.

-L, --copy-links

This tells rsync to treat symbolic links just like ordinary files.

--copy-unsafe-links

This tells rsync to treat symbolic links that point outside the source tree like ordinary files. Absolute symlinks are also treated like ordinary files, and so are any symlinks in the source path itself when --relative is used.

--safe-links

This tells rsync to ignore any symbolic links which point outside the destination tree. All absolute symlinks are also ignored. Using this option in conjunction with --relative may give unexpected results.

-H, --hard-links

This tells rsync to recreate hard links on the remote system to be the same as the local system. Without this option hard links are treated like regular files.

Note that rsync can only detect hard links if both parts of the link are in the list of files being sent.

This option can be quite slow, so only use it if you need it.

-W, --whole-file

With this option the incremental rsync algorithm is not used and the whole file is sent as-is instead. This may be useful when using rsync with a local machine.

-p, --perms

This option causes rsync to update the remote permissions to be the same as the local permissions.

-o, --owner

This option causes rsync to update the remote owner of the file to be the same as the local owner. This is only available to the super-user. Note that if the source system is a daemon using chroot, the --numeric-ids option is implied because the source system cannot get access to the usernames.

-g, --group

This option causes rsync to update the remote group of the file to be the same as the local group. If the receving system is not running as the super-user, only groups that the receiver is a member of will be preserved (by group name, not group id number).

-D, --devices

This option causes rsync to transfer character and block device information to the remote system to recreate these devices. This option is only available to the super-user.

-t, --times

This tells rsync to transfer modification times along with the files and update them on the remote system. Note that if this option is not used, the optimization that excludes files that have not been modified cannot be effective; in other words, a missing -t or -a will cause the next transfer to behave as if it used -I, and all files will have their checksums compared and show up in log messages even if they haven't changed.

-n, --dry-run

This tells rsync to not do any file transfers, instead it will just report the actions it would have taken.

-S, --sparse

Try to handle sparse files efficiently so they take up less space on the destination.

NOTE: Don't use this option when the destination is a Solaris "tmpfs" filesystem. It doesn't seem to handle seeks over null regions correctly and ends up corrupting the files.

-x, --one-file-system

This tells rsync not to cross filesystem boundaries when recursing. This is useful for transferring the contents of only one filesystem.

--existing

This tells rsync not to create any new files - only update files that already exist on the destination.

--max-delete=NUM

This tells rsync not to delete more than NUM files or directories. This is useful when mirroring very large trees to prevent disasters.

--delete

This tells rsync to delete any files on the receiving side that aren't on the sending side. Files that are excluded from transfer are excluded from being deleted unless you use --delete-excluded.

This option has no effect if directory recursion is not selected.

This option can be dangerous if used incorrectly! It is a very good idea to run first using the dry run option (-n) to see what files would be deleted to make sure important files aren't listed.

If the sending side detects any IO errors then the deletion of any files at the destination will be automatically disabled. This is to prevent temporary filesystem failures (such as NFS errors) on the sending side causing a massive deletion of files on the destination.

--delete-excluded

In addition to deleting the files on the receiving side that are not on the sending side, this tells rsync to also delete any files on the receiving side that are excluded (see --exclude).

--delete-after

By default rsync does file deletions before transferring files to try to ensure that there is sufficient space on the receiving filesystem. If you want to delete after transferring then use the --delete-after switch.

--force

This options tells rsync to delete directories even if they are not empty. This applies to both the --delete option and to cases where rsync tries to copy a normal file but the destination contains a directory of the same name.

Since this option was added, deletions were reordered to be done depth-first so it is hardly ever needed anymore except in very obscure cases.

-B , --block_size=BLOCKSIZE

This controls the block size used in the rsync algorithm. See the technical report for details.

-e, --rsh=COMMAND

This option allows you to choose an alternative remote shell program to use for communication between the local and remote copies of rsync. By default, rsync will use rsh, but you may like to instead use ssh because of its high security.

You can also choose the remote shell program using the RSYNC_RSH environment variable.

--rsync-path=PATH

Use this to specify the path to the copy of rsync on the remote machine. Useful when it's not in your path. Note that this is the full path to the binary, not just the directory that the binary is in.

--exclude=PATTERN

This option allows you to selectively exclude certain files from the list of files to be transferred. This is most useful in combination with a recursive transfer.

You may use as many --exclude options on the command line as you like to build up the list of files to exclude.

See the section on exclude patterns for information on the syntax of this option.

--exclude-from=FILE

This option is similar to the --exclude option, but instead it adds all filenames listed in the file FILE to the exclude list. Blank lines in FILE and lines starting with ';' or '#' are ignored.

--include=PATTERN

This option tells rsync to not exclude the specified pattern of filenames. This is useful as it allows you to build up quite complex exclude/include rules.

See the section of exclude patterns for information on the syntax of this option.

--include-from=FILE

This specifies a list of include patterns from a file.

-C, --cvs-exclude

This is a useful shorthand for excluding a broad range of files that you often don't want to transfer between systems. It uses the same algorithm that CVS uses to determine if a file should be ignored.

The exclude list is initialized to:

RCS SCCS CVS CVS.adm RCSLOG cvslog.* tags TAGS .make.state .nse_depinfo *~ #* .#* ,* *.old *.bak *.BAK *.orig *.rej .del-* *.a *.o *.obj *.so *.Z *.elc *.ln core

then files listed in a $HOME/.cvsignore are added to the list and any files listed in the CVSIGNORE environment variable (space delimited).

Finally in each directory any files listed in the .cvsignore file in that directory are added to the list.

--csum-length=LENGTH

By default the primary checksum used in rsync is a very strong 16 byte MD4 checksum. In most cases you will find that a truncated version of this checksum is quite efficient, and this will decrease the size of the checksum data sent over the link, making things faster.

You can choose the number of bytes in the truncated checksum using the --csum-length option. Any value less than or equal to 16 is valid.

Note that if you use this option then you run the risk of ending up with an incorrect target file. The risk with a value of 16 is microscopic and can be safely ignored (the universe will probably end before it fails) but with smaller values the risk is higher.

Current versions of rsync actually use an adaptive algorithm for the checksum length by default, using a 16 byte file checksum to determine if a 2nd pass is required with a longer block checksum. Only use this option if you have read the source code and know what you are doing.

-T, --temp-dir=DIR

This option instructs rsync to use DIR as a scratch directory when creating temporary copies of the files transferred on the receiving side. The default behavior is to create the temporary files in the receiving directory.

--compare-dest=DIR

This option instructs rsync to use DIR as an additional directory to compare destination files against when doing transfers. This is useful for doing transfers to a new destination while leaving existing files intact, and then doing a flash-cutover when all files have been successfully transferred (for example by moving directories around and removing the old directory, although this requires also doing the transfer with -I to avoid skipping files that haven't changed). This option increases the usefulness of --partial because partially transferred files will remain in the new temporary destination until they have a chance to be completed. If DIR is a relative path, it is relative to the destination directory.

-z, --compress

With this option, rsync compresses any data from the source file(s) which it sends to the destination machine. This option is useful on slow links. The compression method used is the same method that gzip uses.

Note this this option typically achieves better compression ratios that can be achieved by using a compressing remote shell, or a compressing transport, as it takes advantage of the implicit information sent for matching data blocks.

--numeric-ids

With this option rsync will transfer numeric group and user ids rather than using user and group names and mapping them at both ends.

By default rsync will use the user name and group name to determine what ownership to give files. The special uid 0 and the special group 0 are never mapped via user/group names even if the --numeric-ids option is not specified.

If the source system is a daemon using chroot, or if a user or group name does not exist on the destination system, then the numeric id from the source system is used instead.

--timeout=TIMEOUT

This option allows you to set a maximum IO timeout in seconds. If no data is transferred for the specified time then rsync will exit. The default is 0, which means no timeout.

--daemon

This tells rsync that it is to run as a rsync daemon. If standard input is a socket then rsync will assume that it is being run via inetd, otherwise it will detach from the current terminal and become a background daemon. The daemon will read the config file (/etc/rsyncd.conf) on each connect made by a client and respond to requests accordingly. See the rsyncd.conf(5) man page for more details.

--address

By default rsync will bind to the wildcard address when run as a daemon with the --daemon option or when connecting to a rsync server. The --address option allows you to specify a specific IP address (or hostname) to bind to. This makes virtual hosting possible in conjunction with the --config option.

--config=FILE

This specifies an alternate config file than the default /etc/rsyncd.conf. This is only relevant when --daemon is specified.

--port=PORT

This specifies an alternate TCP port number to use rather than the default port 873.

--log-format=FORMAT

This allows you to specify exactly what the rsync client logs to stdout on a per-file basis. The log format is specified using the same format conventions as the log format option in rsyncd.conf.

--stats

This tells rsync to print a verbose set of statistics on the file transfer, allowing you to tell how effective the rsync algorithm is for your data.

--partial

By default, rsync will delete any partially transferred file if the transfer is interrupted. In some circumstances it is more desirable to keep partially transferred files. Using the --partial option tells rsync to keep the partial file which should make a subsequent transfer of the rest of the file much faster.

--progress

This option tells rsync to print information showing the progress of the transfer. This gives a bored user something to watch.

This option is normally combined with -v. Using this option without the -v option will produce weird results on your display.

-P

The -P option is equivalent to --partial --progress. I found myself typing that combination quite often so I created an option to make it easier.

--password-file

This option allows you to provide a password in a file for accessing a remote rsync server. Note that this option is only useful when accessing a rsync server using the built in transport, not when using a remote shell as the transport. The file must not be world readable. It should contain just the password as a single line.

 

EXCLUDE PATTERNS

The exclude and include patterns specified to rsync allow for flexible selection of which files to transfer and which files to skip. rsync builds a ordered list of include/exclude options as specified on the command line. When a filename is encountered, rsync checks the name against each exclude/include pattern in turn. The first matching pattern is acted on. If it is an exclude pattern than that file is skipped. If it is an include pattern then that filename is not skipped. If no matching include/exclude pattern is found then the filename is not skipped.
Note that the --include and --exclude options take one pattern each. To add multiple patterns use the --include-from and --exclude-from options or multiple --include and --exclude options.