Hi,
It is most likely that there is some issue with database connectivity if CMS does not start. Please check the Oracle database connectivity from BO server and also confirm whether you have setup the Environment variables ORACLE_HOME and LD_LIBRARY_PATH on the BO server.
The /var/log/messages file gives correct error messages in this situation but you will need root privileges to access this file. Please ask your server admin to give access to this file or get a copy of this file so that we can see the error messages.
Regards,
Hrishikesh