在兩臺機子上同時操作下面的步驟

首先安裝MySQL，從官網下載相對應版本的RPM包

• mysql-community-client-5.7.23-1.el7.x86_64.rpm
• mysql-community-common-5.7.23-1.el7.x86_64.rpm
• mysql-community-libs-5.7.23-1.el7.x86_64.rpm
• mysql-community-libs-compat-5.7.23-1.el7.x86_64.rpm (*解決與XtraBackup安裝時，my.cnf沖突問題)
• mysql-community-server-5.7.23-1.el7.x86_64.rpm

一口氣把他們全都安上，省的報依賴錯誤

rpm -ivh mysql-community-client-5.7.23-1.el7.x86_64.rpm mysql-community-common-5.7.23-1.el7.x86_64.rpm mysql-community-libs-5.7.23-1.el7.x86_64.rpm mysql-community-libs-compat-5.7.23-1.el7.x86_64.rpm mysql-community-server-5.7.23-1.el7.x86_64.rpm

初始化MySQL

先修改 /var/lib/mysql/ 文件夾的權限，因為是用root權限安裝的，需要修改為mysql的權限。

chown -R mysql.mysql /var/lib/mysql/

初始化MySQL

mysqld --initialize

從mysqld.log中獲取初始密碼，得到紅色部分的密碼

[root@localhost srv]# cat /var/log/mysqld.log | grep ‘y password‘
2018-08-23T05:54:39.866279Z 1 [Note] A temporary password is generated for root@localhost: (WRwAWtoj14+

登錄mysql，修改密碼

[root@localhost srv]# mysql -uroot -p‘
 
(WRwAWtoj14+‘
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.23

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.

mysql> alter user root@localhost identified by ‘root‘;
Query OK, 0 rows affected (0.01 sec)

mysql> exit
Bye

至此，MySQL安裝完畢

安裝XtraBackup

按照官網的安裝示例安裝即可：https://www.percona.com/doc/percona-xtrabackup/2.4/installation/yum_repo.html

1、安裝Percona yum 倉庫

yum install http://www.percona.com/downloads/percona-release/redhat/0.1-6/percona-release-0.1-6.noarch.rpm

2、安裝XtraBackup 24

yum install percona-xtrabackup-24 -y

會以依賴安裝（就是因為依賴總是離線安不上，才用的yum）：

作為依賴被安裝:
  libev.x86_64 0:4.15-7.el7   perl-DBD-MySQL.x86_64 0:4.023-6.el7   perl-Digest.noarch 0:1.17-245.el7   
　perl-Digest-MD5.x86_64 0:2.52-3.el7   rsync.x86_64 0:3.1.2-4.el7  

至此，兩個軟件安裝完畢

上面安裝中的一些坑（已經幫助跳過去了）：

1、MySQL無法啟動，cli下報如下錯誤

[root@localhost srv]# service mysqld start
Redirecting to /bin/systemctl start mysqld.service
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.

/var/log/mysqld.log中報如下錯誤

2018-08-23T06:08:24.018182Z 0 [ERROR] InnoDB: The innodb_system data file ‘ibdata1‘ must be writable
2018-08-23T06:08:24.018188Z 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2018-08-23T06:08:24.620670Z 0 [ERROR] Plugin ‘InnoDB‘ init function returned error.
2018-08-23T06:08:24.620698Z 0 [ERROR] Plugin ‘InnoDB‘ registration as a STORAGE ENGINE failed.
2018-08-23T06:08:24.620703Z 0 [ERROR] Failed to initialize builtin plugins.
2018-08-23T06:08:24.620706Z 0 [ERROR] Aborting

解決方法看上面的MySQL初始化部分

2、XtraBackup安裝沖突

file /etc/my.cnf from install of Percona-Server-shared-56-5.6.41-rel84.1.el7.x86_64 conflicts with file from package mysql-community-server-5.7.23-1.el7.x86_64

先安裝 mysql-community-libs-compat-5.7.23-1.el7.x86_64.rpm 即可

CentOS7 下 MySQL 5.7.23 & XtraBackup 24 做數據備份——安裝軟件