a fast, versatile, remote (and local) file-copying tool
This tells rsync to copy directories recursively. See also --dirs (-d).
Beginning with rsync 3.0.0, the recursive algorithm used is now an incremental scan that uses much
less memory than before and begins the transfer after the scanning of the first few directories
have been completed. This incremental scan only affects our recursion algorithm, and does not
change a non-recursive transfer. It is also only possible when both ends of the transfer are at
least version 3.0.0.
Some options require rsync to know the full file list, so these options disable the incremental
recursion mode. These include: --delete-before, --delete-after, --prune-empty-dirs, and
--delay-updates. Because of this, the default delete mode when you specify --delete is now
--delete-during when both ends of the connection are at least 3.0.0 (use --del or --delete-during
to request this improved deletion mode explicitly). See also the --delete-delay option that is a
better choice than using --delete-after.
Incremental recursion can be disabled using the --no-inc-recursive option or its shorter --no-i-r
When symlinks are encountered, recreate the symlink on the destination.
This option causes the receiving rsync to set the destination permissions to be the same as the
source permissions. (See also the --chmod option for a way to modify what rsync considers to be
the source permissions.)
When this option is off, permissions are set as follows:
o Existing files (including updated files) retain their existing permissions, though the
--executability option might change just the execute permission for the file.
o New files get their "normal" permission bits set to the source file’s permissions masked
with the receiving directory’s default permissions (either the receiving process’s umask,
or the permissions specified via the destination directory’s default ACL), and their
special permission bits disabled except in the case where a new directory inherits a setgid
bit from its parent directory.
Thus, when --perms and --executability are both disabled, rsync’s behavior is the same as that of
other file-copy utilities, such as cp(1) and tar(1).
In summary: to give destination files (both old and new) the source permissions, use --perms. To
give new files the destination-default permissions (while leaving existing files unchanged), make
sure that the --perms option is off and use --chmod=ugo=rwX (which ensures that all non-masked
bits get enabled). If you’d care to make this latter behavior easier to type, you could define a
popt alias for it, such as putting this line in the file ~/.popt (the following defines the -Z
option, and includes --no-g to use the default group of the destination dir):
rsync alias -Z --no-p --no-g --chmod=ugo=rwX
You could then use this new option in a command such as this one:
rsync -avZ src/ dest/
(Caveat: make sure that -a does not follow -Z, or it will re-enable the two "--no-*" options
The preservation of the destination’s setgid bit on newly-created directories when --perms is off
was added in rsync 2.6.7. Older rsync versions erroneously preserved the three special permission
bits for newly-created files when --perms was off, while overriding the destination’s setgid bit
setting on a newly-created directory. Default ACL observance was added to the ACL patch for rsync
2.6.7, so older (or non-ACL-enabled) rsyncs use the umask even if default ACLs are present. (Keep
in mind that it is the version of the receiving rsync that affects these behaviors.)
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, causing all files to be updated (though rsync’s delta-transfer
algorithm will make the update fairly efficient if the files haven’t actually changed, you’re much
better off using -t).
This option causes rsync to set the group of the destination file to be the same as the source
file. If the receiving program is not running as the super-user (or if --no-super was specified),
only groups that the invoking user on the receiving side is a member of will be preserved.
Without this option, the group is set to the default group of the invoking user on the receiving
The preservation of group information will associate matching names by default, but may fall back
to using the ID number in some circumstances (see also the --numeric-ids option for a full
This option causes rsync to set the owner of the destination file to be the same as the source
file, but only if the receiving rsync is being run as the super-user (see also the --super and
--fake-super options). Without this option, the owner of new and/or transferred files are set to
the invoking user on the receiving side.
The preservation of ownership will associate matching names by default, but may fall back to using
the ID number in some circumstances (see also the --numeric-ids option for a full discussion).
-D The -D option is equivalent to --devices --specials.