CentOS6.x 下 LNMP环境搭建一、安装 MySQL

CentOS6.x 下 LNMP环境搭建（准备篇）

CentOS6.x 下LNMP环境搭建（一、安装 MySQL）

CentOS6.x 下LNMP环境搭建（二、安装 Nginx）

CentOS6.x 下LNMP环境搭建（三、安装 PHP）

1. 创建用户

# groupadd mysql
# useradd -s /sbin/nologin -g mysql -M mysql

---- 检查----
# tail -1 /etc/passwd
mysql:x:501:501::/home/mysql:/sbin/nologin
# id mysql
uid=501(mysql) gid=501(mysql) groups=501(mysql)
---- 检查 ----
注：也可以用一条命令代替【useradd mysql -s /sbin/nologin -M】

2. 解压、配置

# cd /root/src
# tar -zxvf mysql-5.5.50-linux2.6-x86_64.tar.gz
# mv mysql-5.5.50-linux2.6-x86_64 /lnmp/server/mysql-5.5.50 && cd /lnmp/server
# ls -l
# ln -s /lnmp/server/mysql-5.5.50/ mysql
# ls -l
# cd mysql
# ls -l support-files/*.cnf  <------- 查看所有配置样例
# /bin/cp support-files/my-large.cnf /etc/my.cnf  <------- /bin/cp 直接覆盖重名文件，不提示

3. 初始化数据（是否需要单独挂一个目录？根据需要）

# mkdir -p /data/mysql
# chown -R mysql:mysql /data/mysql
# ./scripts/mysql_install_db --basedir=/lnmp/server/mysql --datadir=/data/mysql --user=mysql
...
Installing MySQL system tables...
160529 18:23:19 [Note] /lnmp/server/mysql/bin/mysqld (mysqld 5.5.50) starting as process 33182 ...
OK
Filling help tables...
160529 18:23:20 [Note] /lnmp/server/mysql/bin/mysqld (mysqld 5.5.50) starting as process 33189 ...
OK

To start mysqld at boot time you have to copy
support-files/mysql.server to the right place for your system
...

注：如上出现两个ok，标识初始化成功；否则失败，需解决初始化错误

4.修改设置并启动服务

# cp ./support-files/mysql.server /etc/init.d/mysqld
# chmod 755 /etc/init.d/mysqld
# sed -i 's#/usr/local/mysql#/lnmp/server/mysql#g' /lnmp/server/mysql/bin/mysqld_safe /etc/init.d/mysqld
  <------- 替换二进制包的默认MySQL安装路径
# vim /etc/init.d/mysqld  <------- 修改 basedir 和 datadir，如下
basedir=/lnmp/server/mysql
datadir=/data/mysql
# /etc/init.d/mysqld start <------- 启动服务
Starting MySQL... SUCCESS!

检查 3306 是否启动：
# netstat -tlunp|grep mysql
tcp    0   0 0.0.0.0:3306   0.0.0.0:*   LISTEN   33457/mysqld

5. 设置开机自启动

# chkconfig --add mysqld
# chkconfig mysqld on
# chkconfig --list|grep mysqld
mysqld     0:off  1:off  2:on  3:on  4:on  5:on  6:off

6. 配置MySQL命令全局使用

# echo 'export PATH=/lnmp/server/mysql/bin:$PATH' >>/etc/profile
# tail -1 /etc/profile <------- 检查写入文件
export PATH=/lnmp/server/mysql/bin:$PATH
# source /etc/profile  <------- 使修改马上生效
# echo $PATH  <------- 检查最终设置结果
/lnmp/server/mysql/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/whoru/bin

7. 登录测试，更改默认管理员密码

# mysql   <------- 输入 mysql 可以直接登录，安装好后默认密码为空
Welcome to the MySQL monitor. Commands end with ; or \g.
.....
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>quit;   <------- 退出 mysql 命令行
# mysqladmin -u root password 'whoru123'  <------- 修改 root 默认的空密码
# mysql
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
# mysql -uroot -p  <------- 必须使用用户名和密码登录
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
.....
mysql>

8. 清理没有用的用户及库

mysql> select user,host from mysql.user;
+------+-----------+
| user | host   |
+------+-----------+
| root | 127.0.0.1 |
| root | ::1    |
|   | localhost |
| root | localhost |
|   | web1   |
| root | web1   |
+------+-----------+
6 rows in set (0.00 sec)

mysql> drop user "root"@"::1";
Query OK,0 rows affected (0.00 sec)

mysql> drop user ""@"localhost";
Query OK,0 rows affected (0.00 sec)

mysql> drop user ""@"web1";
Query OK,0 rows affected (0.00 sec)

mysql> drop user "root"@"web1";
Query OK,0 rows affected (0.01 sec)

mysql> select user,host from mysql.user;
+------+-----------+
| user | host   |
+------+-----------+
| root | 127.0.0.1 |
| root | localhost |
+------+-----------+
2 rows in set (0.00 sec)

mysql> flush privileges;  <------- 清除缓存
Query OK,0 rows affected (0.00 sec)