Hi All,
Thanks for the valuable suggestions .
Resolved the issue , we tried to switched to node 2 and there startsap starts the DB .
Then compared everything between node 1 and 2 . Found some difference in /etc/hosts file , where in node 1 , the database hostname was wrongly added by OS team . We did not check host file before , since hostname,ping -a all were returning the correct DB host logical name , but it seems like startsap first checks the hostfile ,not the DNS .
Changed /etc/hosts with the logical host name of DB corresponding to IP . Now all works fine , fail over, fail back are fine .
Thanks again for your time.
Regards,
Nibu Antony