1、提示异常信息为：Starting MySQL.The server quit without updating PID file (/var/lib/mysql/iZ25g67a3c5Z.pid).[FAILED]
2、查看日志文件iZ25g67a3c5Z.err 显示错误日志为：
140915 10:13:47 mysqld_safe mysqld from pid file /var/lib/mysql/iZ25g67a3c5Z.pid ended
140915 10:15:00 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
140915 10:15:00 [Note] Plugin 'FEDERATED' is disabled.
140915 10:15:00 InnoDB: The InnoDB memory heap is disabled
140915 10:15:00 InnoDB: Mutexes and rw_locks use GCC atomic builtins
140915 10:15:00 InnoDB: Compressed tables use zlib 1.2.3
140915 10:15:00 InnoDB: Using Linux native AIO
140915 10:15:00 InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137363456 bytes) failed; errno 12
140915 10:15:00 InnoDB: Completed initialization of buffer pool
140915 10:15:00 InnoDB: Fatal error: cannot allocate memory for the buffer pool
140915 10:15:00 [ERROR] Plugin 'InnoDB' init function returned error.
140915 10:15:00 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
140915 10:15:00 [ERROR] Unknown/unsupported storage engine: InnoDB
140915 10:15:00 [ERROR] Aborting
140915 10:15:00 [Note] /usr/sbin/mysqld: Shutdown complete
3、解决方法：
这个其实日志里面说的很明白就是 mysql要占用内存的时候 物理内存不够用导致的 所有 vim /etc/my.cnf
innodb_buffer_pool_size=64MB 把这个数值改小 高版本的默认是128mb 版本的默认是8Mb