Linux下安装MySQL

1. 用wget下载MySQL8.0的地址：wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.18-linux-glibc2.12-x86_64.tar.xz
2. 解压.xz文件：xz -d mysql-8.0.18-linux-glibc2.12-x86_64.tar.xz
3. 解压.tar文件：tar -xvf mysql-8.0.18-linux-glibc2.12-x86_64.tar
4. 将解压后的目录移动到/usr/local/下，并改名：mv mysql-8.0.18-linux-glibc2.12-x86_64 /usr/local/mysql
5. 新建data目录：
   cd /usr/local/mysql
   mkdir data
6. 新建mysql用户组和用户：
   groupadd mysql
   useradd -r -s /sbin/nologin -g mysql mysql -d /usr/local/mysql
7. 改变mysql目录及子目录的用户组和所有者：
   cd /usr/local/mysql
   chown -R mysql .
   chgrp -R mysql .
   注意：后面有 .
8. 初始化mysql并配置参数：
   cd /usr/local/mysql/bin
   ./mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data
   如果碰到./mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory错误，执行一下安装：
   yum install -y libaio
9. 此时生成一个临时密码：A temporary password is generated for root@localhost: iA=Fzthz<97j
10. 配置rsa加密：
    cd /usr/local/mysql/bin/
    ./mysql_ssl_rsa_setup --datadir=/usr/local/mysql/data
11. 系统配置文件：
    cd /usr/local/mysql/support-files/
    cp mysql.server /etc/init.d/mysql
12. 配置/etc/init.d/mysql，修改以下两项：
    vi /etc/init.d/mysql
    basedir=/usr/local/mysql
    datadir=/usr/local/mysql/data
13. 启动mysql：sudo service mysql start
    如果出现错误：mysqld_safe error: log-error set to ‘/var/log/mariadb/mariadb.log’, however file don’t exists.
    创建目录和文件，并授权给mysql：
    cd /var/log/
    mkdir mariadb
    cd mariadb
    touch mariadb.log
    cd …
    chown -R mysql:mysql mariadb/
    如果出现错误：mysqld_safe Directory ‘/var/lib/mysql’ for UNIX socket file don’t exists.
    创建目录，并授权给mysql：
    cd /var/lib/
    mkdir mysql
    chown -R mysql:mysql mysql/
    如果出现错误：Starting MySQL.The server quit without updating PID file (/[FAILED]mysql/IOTEDU-S02.pid).
    查错误日志/var/log/mariadb/mariadb.log