Hello Kavin

I assume that you are running your openerp server on a linux machine.

To give log file path for OpenERP server, you need to create log file, and then provide that log file path as parameter while you start openerp server
For example, we have created log file "openerp.log" file in /opt folder by using touch command (command : touch openerp.log), and configuring it's access rights (command : "sudo chmod 777 /opt/openerp.log"), you can pass that file as parameter like,

python openerp-server --logfile=/opt/openerp.log

and now, all server details will be stored into that log file

Regards