rsync is a very useful utility which can be used to take backup or copy data from one filesystem to other. The best part with rysnc is that it considers incremental data while copying and syntax is easy.
rsync is popular with Linux and included in most versions by default. If you don't have rsync in machine you can simply install it by following commands:-
Ubuntu / Debian
sudo ap-get update
sudo apt-get install rsync
RHEL / CentOS
yum install rsync
Solaris
Now rsync is available in Solaris also. Oracle has now started including
rsync in Solaris 10 and Solaris 11. You can also download it from My Oracle Support website or from
here .
Using rsync
Once you have installed rsync you can use it for copying data from one FS to other. Check the the example here
rsync -avzp --ignore-existing --exclude="lost+found" --exclude=".snapshot" /source/ /target/
-p option is very important as it as it preserves all permissions including ACLs.
rsync and NFS
If you want you can also sync the filesystem which is on another server.
One way of doing it is to mount the source or target filesystem as NFS.
Let's say we have mounted the the target filesystem as NFS on source server then the syntax will be:-
rsync -avzp --ignore-existing --exclude="lost+found" --exclude=".snapshot" /source/ /targetNFS/
rsync and ssh
Or, if you don't want to use NFS you can do the same with ssh.
- First exchange ssh keys between the source and destination server so that the servers can ssh to each other.
- Once you ensure that ssh is working fine between the source and destination server let's move ahead.
- In the below example we are initiating rsync from target server so we have mentioned the IP of source server.
rsync -avzp --ignore-existing --exclude="lost+found" --exclude=".snapshot" --rsh='ssh -p 22' root@Source_Server_IP_ADDRESS:/source/ /target/
Scheduling rsync in cron
If you want you can schedule the rsync in cron also. In the below example we will schedule to run the cron job at 3:30 daily.
30 3 * * * rsync -avzp --ignore-existing --exclude="lost+found" --exclude=".snapshot" --rsh='ssh -p 22' root@Source_IP:/source/ /target/ >/dev/null 2>&1
Options available in rsync.
-v, --verbose increase verbosity
-q, --quiet suppress non-error messages
--no-motd suppress daemon-mode MOTD (see 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 don̢۪t 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 backup suffix (default ~ w/o --backup-dir)
-u, --update skip files that are newer on the receiver
--inplace update destination files in-place
--append append data onto shorter files
--append-verify --append w/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 tree
-k, --copy-dirlinks transform symlink to 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 executability
--chmod=CHMOD affect file and/or directory permissions
-A, --acls preserve ACLs (implies -p)
-X, --xattrs preserve extended attributes
-o, --owner preserve owner (super-user only)
-g, --group preserve group
--devices preserve device files (super-user only)
--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 (w/o delta-xfer algorithm)
-x, --one-file-system don̢۪t 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 remote machine
--existing skip creating new files on receiver
--ignore-existing skip updating files that exist on receiver
--remove-source-files sender removes synchronized files (non-dir)
--del an alias for --delete-during
--delete delete extraneous files from dest dirs
--delete-before receiver deletes before transfer (default)
--delete-during receiver deletes during xfer, not before
--delete-delay find deletions during, delete after
--delete-after receiver deletes after transfer, not before
--delete-excluded also delete excluded files from dest dirs
--ignore-errors delete even if there are I/O errors
--force force deletion of dirs even if not empty
--max-delete=NUM don̢۪t delete more than NUM files
--max-size=SIZE don̢۪t transfer any file larger than SIZE
--min-size=SIZE don̢۪t 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 end
-m, --prune-empty-dirs prune empty directory chains from file-list
--numeric-ids don̢۪t 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 don̢۪t skip files that match size and 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 received 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 suffix in LIST
-C, --cvs-exclude auto-ignore files in the same way CVS does
-f, --filter=RULE add a file-filtering RULE
-F same as --filter=̢۪dir-merge /.rsync-filter̢۪
repeated: --filter=̢۪- .rsync-filter̢۪
--exclude=PATTERN exclude files matching PATTERN
--exclude-from=FILE read exclude patterns from FILE
--include=PATTERN don̢۪t 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; wildcard chars only
--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 we̢۪re 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 dest
--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 (see below for -h comment)
