When working with two or more servers it’s important to know that the files are the same on all servers involved. This script will assist in showing the differences between the servers without actually acting on the differences (will not copy any files).
Key part of the command below is “-n, –dry-run perform a trial run with no changes made” what that means is you could run this command all day and it wouldn’t change any files, useful if things are really out of sync.
rsync -avrcn /opt/* dkittell@192.168.1.2:/opt/
Usage: rsync [OPTION]… SRC [SRC]… DEST
or rsync [OPTION]… SRC [SRC]… [USER@]HOST:DEST
or rsync [OPTION]… SRC [SRC]… [USER@]HOST::DEST
or rsync [OPTION]… SRC [SRC]… rsync://[USER@]HOST[:PORT]/DEST
or rsync [OPTION]… [USER@]HOST:SRC [DEST]
or rsync [OPTION]… [USER@]HOST::SRC [DEST]
or rsync [OPTION]… rsync://[USER@]HOST[:PORT]/SRC [DEST]
The ‘:’ usages connect via remote shell, while ‘::’ & ‘rsync://’ usages connect
to an rsync daemon, and require SRC or DEST to start with a module name.
Options
-v, –verbose increase verbosity
-q, –quiet suppress non-error messages
–no-motd suppress daemon-mode MOTD (see manpage caveat)
-c, –checksum skip based on checksum, not mod-time & size
-a, –archive archive mode; equals -rlptgoD (no -H,-A,-X)
–no-OPTION turn off an implied OPTION (e.g. –no-D)
-r, –recursive recurse into directories
-R, –relative use relative path names
–no-implied-dirs don’t send implied dirs with –relative
-b, –backup make backups (see –suffix & –backup-dir)
–backup-dir=DIR make backups into hierarchy based in DIR
–suffix=SUFFIX set backup suffix (default ~ w/o –backup-dir)
-u, –update skip files that are newer on the receiver
–inplace update destination files in-place (SEE MAN PAGE)
–append append data onto shorter files
–append-verify like –append, but with old data in file checksum
-d, –dirs transfer directories without recursing
-l, –links copy symlinks as symlinks
-L, –copy-links transform symlink into referent file/dir
–copy-unsafe-links only “unsafe” symlinks are transformed
–safe-links ignore symlinks that point outside the source tree
-k, –copy-dirlinks transform symlink to a dir into referent dir
-K, –keep-dirlinks treat symlinked dir on receiver as dir
-H, –hard-links preserve hard links
-p, –perms preserve permissions
-E, –executability preserve the file’s executability
–chmod=CHMOD affect file and/or directory permissions
-A, –acls preserve ACLs (implies –perms)
-X, –xattrs preserve extended attributes
-o, –owner preserve owner (super-user only)
-g, –group preserve group
–devices preserve device files (super-user only)
–copy-devices copy device contents as regular file
–specials preserve special files
-D same as –devices –specials
-t, –times preserve modification times
-O, –omit-dir-times omit directories from –times
–super receiver attempts super-user activities
–fake-super store/recover privileged attrs using xattrs
-S, –sparse handle sparse files efficiently
-n, –dry-run perform a trial run with no changes made
-W, –whole-file copy files whole (without delta-xfer algorithm)
-x, –one-file-system don’t cross filesystem boundaries
-B, –block-size=SIZE force a fixed checksum block-size
-e, –rsh=COMMAND specify the remote shell to use
–rsync-path=PROGRAM specify the rsync to run on the remote machine
–existing skip creating new files on receiver
–ignore-existing skip updating files that already exist on receiver
–remove-source-files sender removes synchronized files (non-dirs)
–del an alias for –delete-during
–delete delete extraneous files from destination dirs
–delete-before receiver deletes before transfer, not during
–delete-during receiver deletes during the transfer
–delete-delay find deletions during, delete after
–delete-after receiver deletes after transfer, not during
–delete-excluded also delete excluded files from destination dirs
–ignore-errors delete even if there are I/O errors
–force force deletion of directories even if not empty
–max-delete=NUM don’t delete more than NUM files
–max-size=SIZE don’t transfer any file larger than SIZE
–min-size=SIZE don’t transfer any file smaller than SIZE
–partial keep partially transferred files
–partial-dir=DIR put a partially transferred file into DIR
–delay-updates put all updated files into place at transfer’s end
-m, –prune-empty-dirs prune empty directory chains from the file-list
–numeric-ids don’t map uid/gid values by user/group name
–timeout=SECONDS set I/O timeout in seconds
–contimeout=SECONDS set daemon connection timeout in seconds
-I, –ignore-times don’t skip files that match in size and mod-time
–size-only skip files that match in size
–modify-window=NUM compare mod-times with reduced accuracy
-T, –temp-dir=DIR create temporary files in directory DIR
-y, –fuzzy find similar file for basis if no dest file
–compare-dest=DIR also compare destination files relative to DIR
–copy-dest=DIR … and include copies of unchanged files
–link-dest=DIR hardlink to files in DIR when unchanged
-z, –compress compress file data during the transfer
–compress-level=NUM explicitly set compression level
–skip-compress=LIST skip compressing files with a suffix in LIST
-C, –cvs-exclude auto-ignore files the same way CVS does
-f, –filter=RULE add a file-filtering RULE
-F same as –filter=’dir-merge /.rsync-filter’
repeated: –filter=’- .rsync-filter’
–exclude=PATTERN exclude files matching PATTERN
–exclude-from=FILE read exclude patterns from FILE
–include=PATTERN don’t exclude files matching PATTERN
–include-from=FILE read include patterns from FILE
–files-from=FILE read list of source-file names from FILE
-0, –from0 all *-from/filter files are delimited by 0s
-s, –protect-args no space-splitting; only wildcard special-chars
–address=ADDRESS bind address for outgoing socket to daemon
–port=PORT specify double-colon alternate port number
–sockopts=OPTIONS specify custom TCP options
–blocking-io use blocking I/O for the remote shell
–stats give some file-transfer stats
-8, –8-bit-output leave high-bit chars unescaped in output
-h, –human-readable output numbers in a human-readable format
–progress show progress during transfer
-P same as –partial –progress
-i, –itemize-changes output a change-summary for all updates
–out-format=FORMAT output updates using the specified FORMAT
–log-file=FILE log what we’re doing to the specified FILE
–log-file-format=FMT log updates using the specified FMT
–password-file=FILE read daemon-access password from FILE
–list-only list the files instead of copying them
–bwlimit=KBPS limit I/O bandwidth; KBytes per second
–write-batch=FILE write a batched update to FILE
–only-write-batch=FILE like –write-batch but w/o updating destination
–read-batch=FILE read a batched update from FILE
–protocol=NUM force an older protocol version to be used
–iconv=CONVERT_SPEC request charset conversion of filenames
–checksum-seed=NUM set block/file checksum seed (advanced)
-4, –ipv4 prefer IPv4
-6, –ipv6 prefer IPv6
–version print version number
(-h) –help show this help (-h is –help only if used alone)