昨天使用rpm安装了一个mysql最新版本，在安装的时候因为系统里面自带了mysql5.1的版本。所以我在安装mysql5.5的时候一直报错，故使用yum -y remove mysql*将老版本的安装包移除，然后才将其安装成功，因为是rpm安装，不能更改安装路径，注意！后面因为要迁移环境，故需要将data的存放路径修改一下，于是我vi /etc/init.d/mysql 进去之后将datadir指到了？/opt/reuters/dds 。保存之后为了让配置文件生效就需要重启进程，ok，这下好了，进程不能停止也不能启动了，使用/etc/init.d/mysql stop 总是报这个错，ERROR! MySQL server PID file could not be found!，进去data目录下查看使用localhost.localdomain.err 查看报错信息，

InnoDB: the directory.

InnoDB: File name ./ibdata1

InnoDB: File operation call: 'create'.

InnoDB: Cannot continue operation.

130613 17:42:05 mysqld_safe mysqld from pid file /opt/reuters/dds/data/localhost.localdomain.pid ended

130613 17:46:44 mysqld_safe Starting mysqld daemon with databases from /opt/reuters/dds/data

130613 17:46:44 [Note] Plugin 'FEDERATED' is disabled.

/usr/sbin/mysqld: Table 'mysql.plugin' doesn't exist

130613 17:46:44 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.

130613 17:46:44 InnoDB: The InnoDB memory heap is disabled

130613 17:46:44 InnoDB: Mutexes and rw_locks use GCC atomic builtins

130613 17:46:44 InnoDB: Compressed tables use zlib 1.2.3

130613 17:46:44 InnoDB: Using Linux native AIO

130613 17:46:44 InnoDB: Initializing buffer pool, size = 128.0M

130613 17:46:44 InnoDB: Completed initialization of buffer pool

130613 17:46:44  InnoDB: Operating system error number 13 in a file operation.

InnoDB: The error means mysqld does not have the access rights to

ps -ef | grep mysql 进程也不存在开得太多卡死这一说，网上说的基本都是让在初始化权限表时使用shell> ..../mysql_install_db --user=mysql --datadir=/usr/local/mysql/var，说真的我还真不会这样操作，后来在万般无奈之下有打开配置文件，在datadir后面又加了一级目录mysql，datadir=/opt/reuters/data/mysql.奇迹出现了，重启进程成功，问题是解决了。希望这个可以对处理mysql报错信息的童鞋有帮助哈