Another MySQL daemon already running with the same unix socket

• 1 To prevent the problem from occurring, you must perform a graceful shutdown of the server from the command line rather than powering off the server.
  
• 2 shutdown -h now
  
• 3 Based on Centos, an additional method for getting it back up again when you run into this problem is to move mysql.sock:
  
• 4 mv /var/lib/mysql/mysql.sock /var/lib/mysql/mysql.sock.bak
  
• 5 service mysqld start
  

References

• http://stackoverflow.com/questions/20407292/centos-another-mysql-daemon-already-running-with-the-same-unix-socket