Some InnoDB error in Mysql log, Pls. help! (2 replies)

Below is the detail:
110903 21:30:17 InnoDB: Error: the OS said file flush did not succeed
110903 21:30:17 InnoDB: Operating system error number 5 in a file operation.
InnoDB: Error number 5 means 'Input/output error'.
InnoDB: Some operating system error numbers are described at
InnoDB: http://dev.mysql.com/doc/refman/5.1/en/operating-system-error-codes.html
InnoDB: File operation call: 'flush'.
InnoDB: Cannot continue operation.

As mysql hangs up, other application depends on it also blocked, then causes system blocked. Can anyone help on this, thanks a lot !