Hi Pathak
Kindly refer the SAP
743328 - Composite SAP note: ORA-27102
546006 - Problems with Oracle due to operating system errors
1478351 - Oracle 11g Support on UNIX: 6.40-Based SAP Systems
1478350 - Obsolete: Oracle 11g Support on UNIX: 7.0<x>-SAP Systems
789011 - FAQ: Oracle memory areas
Regards
Ram