VCS upgrade issue
After upgrading VCS to 5.1 CRS came up normally but database startup failed with error,
ORA-27504: IPC error creating OSD context ORA-27300: OS system dependent operation:lcin: LMXIOC_GETVERSION failed: failed with status: 122 ORA-27301: OS failure message: Operation not supported on transport endpoint ORA-27302: failure occurred at: vcsipc_lmxci ORA-27303: additional information: lcin: LMXIOC_GETVERSION failed: errno 122[Operation not supported on transport endpoint], fd 13, c0x1069017d8
MOS was not able to troubleshoot the issues, but the fix came from Veritas. The solution is here http://sfdoccentral.symantec.com/sf/5.1SP1/linux/html/sfrac_install/ch16s01.htm
I am sure this will be helpful for someone in the future, so that they will save their weekend.