ORA-27123: unable to attach to shared memory segment

ORA-27123: unable to attach to shared memory segment 
SVR4 Error: 13: Permission denied

Cause

This error encounters  probably in a Linux O/S due to permission problem.

 Solution

-         In order to resolve the respective is issue, you can do the following:  

      

        1.) Check the file permission of a file name "oracle" in the Oracle home bin directory.

             ls -l $ORACLE_HOME/bin/oracle

  

2     2.) The respective file will have the permission (of either 755 or 777 ) according to the way you have set it. Ensure the respective file name "oracle" is owned by oracle and not other user.

   

3      3.) And execute the following command:

             chmod 6751 $ORACLE_HOME/bin/oracle