mysqld dead but subsys locked 解决方法

mysql运行时好好的。突然出现以下问题：

#Service mysqld status

 mysqld dead but subsys locked

使用下以命令提示：

# service mysqld start

touch: cannot touch '/var/log/mysqld.log': Read-only file system
chown: changing ownership of '/var/log/mysqld.log': Read-only file system
chmod: changing permissions of '/var/log/mysqld.log': Read-only file system
chown: changing ownership of '/var/lib/mysql': Read-only file system
chmod: changing permissions of '/var/lib/mysql': Read-only file system

查看/var分区，也不能新建文件。

分区成了只读分区，奇怪了。

重新修改分区挂载选项。重启系统OK。