What is “rsync”?

It is a useful Linux utility mostly used for copying files between folders, but it also has extra features that makes of it a powerful tool.

How to install “rsync” con CentOS 7?

The installation of “rsync” is really easy, either using the “root” account or another user with “sudo” privileges, you can use the following CLI command.

yum install rsync

The installation speed depends on the contracted Internet Speed but also depends on how close you are located to the repository containing the software, the following animations shows the whole installation process.

Installing “rsync” on CentOS 7

Installation log

[root@centos7 ~]# yum install rsync
Loaded plugins: fastestmirror
Determining fastest mirrors
 * base:
 * extras:
 * updates:
base                                                                     | 3.6 kB  00:00:00     
extras                                                                   | 2.9 kB  00:00:00     
updates                                                                  | 2.9 kB  00:00:00     
(1/4): base/7/x86_64/group_gz                                            | 165 kB  00:00:16     
(2/4): extras/7/x86_64/primary_db                                        | 159 kB  00:00:16     
(3/4): base/7/x86_64/primary_db                                          | 6.0 MB  00:00:17     
(4/4): updates/7/x86_64/primary_db                                       | 6.7 MB  00:00:21     
Resolving Dependencies
--> Running transaction check
---> Package rsync.x86_64 0:3.1.2-6.el7_6.1 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

 Package            Arch                Version                         Repository         Size
 rsync              x86_64              3.1.2-6.el7_6.1                 base              404 k

Transaction Summary
Install  1 Package

Total download size: 404 k
Installed size: 815 k
Is this ok [y/d/N]: y
Downloading packages:
warning: /var/cache/yum/x86_64/7/base/packages/rsync-3.1.2-6.el7_6.1.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
Public key for rsync-3.1.2-6.el7_6.1.x86_64.rpm is not installed
rsync-3.1.2-6.el7_6.1.x86_64.rpm                                         | 404 kB  00:00:15     
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Importing GPG key 0xF4A80EB5:
 Userid     : "CentOS-7 Key (CentOS 7 Official Signing Key) <>"
 Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5
 Package    : centos-release-7-7.1908.0.el7.centos.x86_64 (@anaconda)
 From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Is this ok [y/N]: y
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : rsync-3.1.2-6.el7_6.1.x86_64                                                 1/1 
  Verifying  : rsync-3.1.2-6.el7_6.1.x86_64                                                 1/1 

  rsync.x86_64 0:3.1.2-6.el7_6.1                                                                


How to use “rsync”

You can always take a look at the man page of every tool you install on your Linux, to learn about advances features, but in the case of “rsync” the following CLI shows the most commonly used function, it is copying files between folders.

rsync -options source destination

rsync man page

man rsync

rsync man page

rsync options summary

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

        -v, --verbose               increase verbosity
            --info=FLAGS            fine-grained informational verbosity
            --debug=FLAGS           fine-grained debug verbosity
            --msgs2stderr           special output handling for debugging
        -q, --quiet                 suppress non-error messages
            --no-motd               suppress daemon-mode MOTD (see caveat)
        -c, --checksum              skip based on checksum, not mod-time &amp; 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 &amp; --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
            --munge-links           munge symlinks to make them safer
        -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)
            --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
        -J, --omit-link-times       omit symlinks from --times
            --super                 receiver attempts super-user activities
            --fake-super            store/recover privileged attrs using xattrs
        -S, --sparse                handle sparse files efficiently
            --preallocate           allocate dest files before writing
        -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       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 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 xfer, 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 dest dirs
            --ignore-missing-args   ignore missing source args without error
            --delete-missing-args   delete missing source args from destination
            --ignore-errors         delete even if there are I/O errors
            --force                 force deletion of dirs 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 end
        -m, --prune-empty-dirs      prune empty directory chains from file-list
            --numeric-ids           don't map uid/gid values by user/group name
            --usermap=STRING        custom username mapping
            --groupmap=STRING       custom groupname mapping
            --chown=USER:GROUP      simple username/groupname mapping
            --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 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-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; 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
            --outbuf=N|L|B          set out buffering to None, Line, or Block
            --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
        -M, --remote-option=OPTION  send OPTION to the remote side only
            --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=RATE          limit socket I/O bandwidth
            --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)

-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.

WordPress and rsync

A good use case for “rsync” could be when installing WordPress, let’s say you’ve downloaded the latest WordPress version from the official website and after decompressing the file into your home directory, now you have to copy them to their final destination in that case you can use “rsync” as follow:

rsync -avP ~/wordpress/ /var/www/html/

The destination folder of the above command applies to cases where Apache is not configured to use Virtual Hosts, if you want to learn about Apache and Virtual Host you can take a look at this article.

Where was “rsync” installed?

Aren’t you curious about where in your system was “rsync” installed, if so here you are a few CLI command which can assist you.

whereis rsync

whereis tool

which rsync

which tool

Places where executable code lives

The preceding tools “whereis” and “which” will show you the path where the executable files end up after the installation process, these folders are also mapped in the environmental variable $PATH for the system to know that these files can be executed from anywhere.

echo $PATH

$PATH environmental vaiable.

$PATH Environmental Variable

$PATH is an Environment Variable used to specify a set of directories where executable programs are located, in general either for Windows, Linux or Mac, each executing process or user session has its own PATH setting.

See all the files installed

If you want to know all the files that have been installed by a particular YUM package, then you can use one of the “yum utils” tools called “repoquery”.

repoquery --list rsync


As you can see in the above output, in Linux most programs don’t usually end up in a single directory, but in different ones instead (executables, configuration files, log files, documentation, etc.) are scattered through the filesystem.