CMS down, unknown reason - not able to start up

./ccm.sh -display # gives the follwoing message..

Creating session manager...

Logging onto CMS...

err: Error: Couldn't logon to CMS

err: Error description: The system business1 can be contacted, but there is no Central Management Server running at port 6400.

I tried restarting the tomcat and the all the BO servers, but the cms is still down. How can I resolve this issue, or find out more about what is happening.

Thanks.