十一

#
The rsync server does not need to start the rsync daemon process; as long as you obtain the username and password of the remote host, you can directly rsync to synchronize files.
#
Since the rsync server does not start the daemon process, there is no need for the configuration file /etc/rsyncd.conf.

//This method omits -e ssh by default and is equivalent to the following:
rsync -avz /SRC -e ssh [email protected]:/DEST 
    -a  //File owner changes, timestamp remains the same
    -V  //Display detailed information during the process
    -z  //Compress data during transmission

//When needing to change the port, we can:
#Change the port of the ssh protocol, default is 22
rsync -avz /SRC -e "ssh -p2222" [email protected]:/DEST

#Check which package the rsync command requires
[root@node1 ~]# yum provides */bin/rsync
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rsync-3.1.3-9.el8.x86_64 : A program for synchronizing files over a network
Repo        : @System
Matched from:
Filename    : /usr/bin/rsync

rsync-3.1.3-9.el8.x86_64 : A program for synchronizing files over a network
Repo        : base
Matched from:
Filename    : /usr/bin/rsync

#Install the rsync command
[root@node1 ~]# yum -y install rsync

#Installation successful
[root@node1 ~]# which rsync
/usr/bin/rsync

//Common formats of the rsync command are as follows:
    rsync [OPTION]... SRC DEST
    rsync [OPTION]... SRC [USER@]HOST:DEST
    rsync [OPTION]... [USER@]HOST:SRC DEST

//Corresponding to the above three command formats, rsync has three different working modes:
1) Copy local files. This mode is activated when neither SRC nor DEST path information contains a single colon ":" separator.
#Command example
[root@localhost ~]# rsync -avz abc /opt/123
2) Use a remote shell program (like rsh, ssh) to copy content from the local machine to the remote machine. This mode is activated when the DST path contains a single colon ":" separator.
#Command example
[root@localhost ~]# ssh [email protected] 'ls -l /root'
3) Use a remote shell program (like rsh, ssh) to copy content from the remote machine to the local machine. This mode is activated when the SRC path contains a single colon ":" separator.
#Command example
[root@localhost ~]# rsync -avz [email protected]:/etc/yum.repos.d /root/

-v, --verbose         Detailed output mode
-q, --quiet           Minimal output mode
-c, --checksum        Enable checksum switch, forcing file transfer verification
-a, --archive         Archive mode, indicating recursive file transfer while preserving all file attributes, equivalent to -rlptgoD
-r, --recursive       Process subdirectories recursively
-R, --relative        Use relative path information
-b, --backup          Create backups, meaning that when a file with the same name already exists at the destination, the old file will be renamed to ~filename. You can use the --suffix option to specify a different backup file prefix.
--backup-dir          Store backup files (like ~filename) in a specified directory.
-suffix=SUFFIX        Define the backup file prefix
-u, --update          Only update, meaning skip all files that already exist in DST and have a later timestamp than the file to be backed up. (Do not overwrite updated files)
-l, --links           Preserve soft links
-L, --copy-links      Treat soft links as regular files
--copy-unsafe-links   Only copy links pointing outside the SRC path directory tree
--safe-links          Ignore links pointing outside the SRC path directory tree
-H, --hard-links      Preserve hard links
-p, --perms           Preserve file permissions
-o, --owner           Preserve file owner information
-g, --group           Preserve file group information
-D, --devices         Preserve device file information
-t, --times           Preserve file timestamp information
-S, --sparse          Special handling of sparse files to save space in DST
-n, --dry-run         Show which files will be transferred
-W, --whole-file      Copy files without performing incremental checks
-x, --one-file-system Do not cross filesystem boundaries
-B, --block-size=SIZE Block size used for the checksum algorithm, default is 700 bytes
-e, --rsh=COMMAND     Specify using rsh or ssh for data synchronization
--rsync-path=PATH     Specify the path of the rsync command on the remote server
-C, --cvs-exclude     Automatically ignore files using the same method as CVS, to exclude files that you do not want to transfer
--existing            Only update files that already exist in DST, without backing up newly created files
--delete              Delete files in DST that are not in SRC
--delete-excluded     Also delete files on the receiving end that are specified to be excluded by this option
--delete-after        Delete after the transfer is complete
--ignore-errors       Delete even if there are IO errors
--max-delete=NUM      Delete at most NUM files
--partial             Keep files that were not fully transferred for faster subsequent transfers
--force               Force deletion of directories, even if not empty
--numeric-ids         Do not match numeric user and group IDs to usernames and group names
--timeout=TIME        IP timeout, in seconds
-I, --ignore-times    Do not skip files with the same timestamp and length
--size-only           When deciding whether to back up files, only check file size without considering file time
--modify-window=NUM   Determine the timestamp window used when files have the same time, default is 0
-T --temp-dir=DIR     Create temporary files in DIR
--compare-dest=DIR    Compare files in DIR to determine whether backup is needed
-P                    Equivalent to --partial
--progress            Display the backup process
-z, --compress        Compress files during transmission
--exclude=PATTERN     Specify patterns of files to exclude from transfer
--include=PATTERN     Specify patterns of files to include for transfer
--exclude-from=FILE   Exclude files specified by patterns in FILE
--include-from=FILE   Include files matching patterns specified in FILE
--version             Print version information
--address             Bind to a specific address
--config=FILE         Specify an alternative configuration file, not using the default rsyncd.conf file
--port=PORT           Specify an alternative rsync server port
--blocking-io         Use blocking IO for remote shell
-stats                Provide transfer status for certain files
--progress            Display transfer progress
--log-format=formAT   Specify log file format
--password-file=FILE  Get password from FILE
--bwlimit=KBPS        Limit I/O bandwidth, KBytes per second
-h, --help            Display help information

# Command format
rsync [OPTION...] SRC... [DEST]

# Command format
# Pull
rsync [OPTION...] [USER]@HOST:SRC... [DEST]

# Push
rsync [OPTION] SRC... [USER]@HOST:DEST