[root@localhost ~]# yum -y install mariadb-server
      [root@localhost ~]# systemctl start mariadb
      [root@localhost ~]# mkdir /backup

      案例1:mysql物理备份及恢复
      [root@localhost ~]# tar -cJf /backup/mysql.tar.xz /var/lib/mysql
      [root@localhost ~]# rm -rf /var/lib/mysql/*
      [root@localhost ~]# tar -xf /backup/mysql.tar.xz -C /

      案例2:mysql物理备份及恢复
      [root@localhost ~]# cd /var/lib/mysql
      [root@localhost mysql]# tar -cJf /backup/mysql.tar.xz *
      [root@localhost mysql]# tar -xf /backup/mysql.tar.xz -C /var/lib/mysql

      案例3:host A /etc (海量小文件) ————> host A /tmp
      [root@localhost ~]# tar -czf etc.gz /etc -C /tmp

      [root@localhost ~]# tar -czf - /etc | tar -xzf - -C /tmp
      案例4:host A /etc (海量小文件) ————> host B /tmp
      常规方法:
      [root@localhost ~]# scp -r /etc 172.16.20.21:/tmp
      建议方法:
      ==host B 监听端口==
      [root@w_hat ~]# firewall-cmd —permanent —add-port=8888/tcp
      [root@w_hat ~]# firewall-cmd —reload
      或
      [root@hostb ~]# systemctl stop firewalld.service
      [root@hostb ~]# nc -l 8888 |tar -xzf - -C /tmp
      ==host A ==
      [root@localhost ~]# tar -czf - /etc | nc 172.16.20.21 8888
      tar: Removing leading `/‘ from member names