ERROR 1018 (HY000): Can't read dir of './cmp/' (errno: 13)

1、错误描述

root@localhost 15:54:  [cmp]> show tables;
ERROR 1018 (HY000): Can't read dir of './cmp/' (errno: 13)
root@localhost 15:54:  [cmp]> show tables;
ERROR 1018 (HY000): Can't read dir of './cmp/' (errno: 13)

root@localhost 16:01:  [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| cmp                |
| mysql              |
| student            |
| test               |
+--------------------+
5 rows in set (0.00 sec)

root@localhost 16:02:  [(none)]> drop database cmp;
ERROR 1008 (HY000): Can't drop database 'cmp'; database doesn't exist
root@localhost 16:02:  [(none)]> create database cmp;
ERROR 1006 (HY000): Can't create database 'cmp' (errno: 13)
root@localhost 16:02:  [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| cmp                |
| mysql              |
| student            |
| test               |
+--------------------+
5 rows in set (0.00 sec)

[yhd@localhost 桌面]$ mysql -uroot -p
Enter password: 
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
[yhd@localhost 桌面]$ 

[yhd@localhost 桌面]$ mysql -uroot -p
Enter password: 
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
[yhd@localhost 桌面]$ service mysqld start
Starting MySQL. ERROR! Manager of pid-file quit without updating file.

2、错误原因

     在CentOS系统上，创建和删除数据库cmp，但是数据库目录权限被限制了，导致出现这个错误

3、解决办法

      修改mysql数据库目录文件权限

chown -R mysql:mysql /data/mysql