在centos5.2下安装5.1.30的时候出现如下mysql错误
MySQL manager orserverPIDfilecould not befound![FAILED]
Starting MySQL.Manager of pid-file quit without updating file.[FAILED]mysql

查看错误日志
默认的mysql错误日志是在/usr/local/mysql/data 下面  more  ****.err  有下面的信息

090302 02:27:26 mysqld_safe mysqld from pid file /opt/mysql/web2.pid ended
090302 02:30:03 mysqld_safe Starting mysqld daemon with databases from /opt/mysql
090302  2:30:03 [ERROR] /usr/local/mysql/libexec/mysqld: unknown option'--skip-federated'
090302  2:30:03 [ERROR] Aborting

解决方法：

只要将/etc/my.cnf里面的 skip federated注释掉即可。