Error on ibdata1...

Hello experts,
I found sudden error in error logs. Please let me know how to resolve it.

InnoDB: Unable to lock ./ibdata1, error: 11
[Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.


It look likes you are running two mysql instances on same port. Check with

$ ps -aux | grep -v grep | grep mysql

Kill the processes and start mysqld again.

Hi Mirfan,
I check the process but there is only one process is running . I had checked logs & found couple of time same error occur. During that time mysql is running fine & only single process was running.

Is there any other way to debug ?

During process monitoring i found a single user was connected multiple time and chocking the connection cause max_connection reached error & doing nothing. Command were in Sleep state & info were NULL.(this may not be db issue). Why this situation error ?