CentOS7 下 MySQL 5.7.23 & XtraBackup 24 做数据备份（1）——安装软件

在两台机子上同时操作下面的步骤

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首先安装MySQL，从官网下载相对应版本的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 (*解决与XtraBackup安装时，my.cnf冲突问题)
• mysql-community-server-5.7.23-1.el7.x86_64.rpm

一口气把他们全都安上，省的报依赖错误

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/ 文件夹的权限，因为是用root权限安装的，需要修改为mysql的权限。

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

初始化MySQL

mysqld --initialize

从mysqld.log中获取初始密码，得到红色部分的密码

[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+

登录mysql，修改密码

[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安装完毕

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安装XtraBackup

按照官网的安装示例安装即可：https://www.percona.com/doc/percona-xtrabackup/2.4/installation/yum_repo.html

1、安装Percona yum 仓库

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

2、安装XtraBackup 24

yum install percona-xtrabackup-24 -y

会以依赖安装（就是因为依赖总是离线安不上，才用的yum）：

作为依赖被安装:
  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，两个软件安装完毕

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上面安装中的一些坑（已经帮助跳过去了）：

1、MySQL无法启动，cli下报如下错误

[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中报如下错误

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

解决方法看上面的MySQL初始化部分

2、XtraBackup安装冲突

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

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