rsync is a remote and fast incremental backup tool that supports local, ssh and rsync host synchronization.
rsync is one of the basic components of the default Linux/Unix system installation, so we don't need to install it manually.

[root@mysql /]# rpm -q rsync
rsync-3.0.9-17.el7.x86_64

rsync programs do not have configuration files, so we need to write our own:

[root@mysql /]# vim /etc/rsyncd.conf 
....... Omit part of content
uid = nobody                 
gid = nobody
use chroot = yes                           // Imprisonment in source directory
address = 192.168.1.10               // Monitoring address can be omitted
port 873                                        // Monitor port
log file = /var/log/rsyncd.log          // Specify log file location
pid file = /var/run/rsyncd.pid         // File location where process ID is stored
[mysql]                                         // Shared module name
        path = /usr/local/mysql/data      // The path of the source directory
        comment = aaaa                     // Description can be omitted
        read only = no                         // Whether it's read-only or not, no can read or write
        dont compress   = *.gz *.tgz *.zip *.z *.Z *.rpm *.deb *.bz2        // File types that are no longer compressed at synchronization
        auth users = zs                        // Authorized account
        secrets file = /etc/rsyncd_users.db             // Data files for storing account information

rsync has its own account document, so it only needs to write account information in the account document.

[root@mysql /]# vim /etc/rsyncd_users.db 
zs:123.com                   // User name before password
[root@mysql /]# chmod 600 /etc/rsyncd_users.db       # The account is stored in clear text, so it is necessary to adjust the file permissions. 

Backup users need to have corresponding access to the source directory / usr/local/mysql/data:

[root@mysql /]# chmod -R 755 /usr/local/mysql/data/
[root@mysql /]# ll -d /usr/local/mysql/data/
drwxr-xr-x 5 mysql mysql 160 Aug 21 15:15 /usr/local/mysql/data/

Start the rsync service program with the running parameter of "--daemon"

[root@mysql/]# Rsync -- daemon # boot
 To shut down rsync services, kill processes can be used:
[root@mysql/]# kill $(cat/var/run/rsyncd.pid)# stop

Used locally:

[root@localhost /]# rsync /etc/passwd /opt/               # In this local command, the individual feels useless, as opposed to direct cp replication
[root@localhost /]# rsync -rl /etc/passwd /opt/                   # - r denotes recursive entire directory tree-l for backing up linked files

Download (Download):

[root@localhost backup]# rsync -avz   zs@192.168.1.10::mysql   /backup/
Password:                // Input password
//or
[root@localhost /]# rsync -avz rsync://zs@192.168.1.10/mysql /backup/
Password: 

Upload (Upload):

[root@localhost /]# rsync -avz  /backup/  zs@192.168.1.10::mysql
Password:                                  // If backup / no, it means uploading the directory, and if it does, uploading the files in the directory.

Some common backup options for rsync:


Backup work in a real production environment is often repeated as planned, so a task plan is needed:

[root@localhost /]# vim /etc/server.pass              # To avoid entering a password during synchronization, create a password file
123.com
[root@localhost /]# chmod 600 /etc/server.pass                 # Configuration authority
[root@localhost /]# crontab -e 
30      22      *       *       *       /usr/bin/rsync -avz --delete --password-file=/e
tc/server.pass zs@192.168.1.10::mysql /backup
[root@localhost /]# systemctl status crond.service                 # Ensure that the service is started
● crond.service - Command Scheduler
   Loaded: loaded (/usr/lib/systemd/system/crond.service; enabled; vendor preset: enabled)
   Active: active (running) since Four 2019-08-22 00:37:47 CST; 13min ago
 Main PID: 1005 (crond)
   CGroup: /system.slice/crond.service
           └─1005 /usr/sbin/crond -n