title: ORA-27101: shared memory realm does not exist
body: <p>i am facing this error when i start the oracle. I checked Oracle Home and SID. everything is set properly.</p>
  
  <blockquote>
    <p>ORA-27101: shared memory realm does not exist</p>
  </blockquote>
  
  <p>please help me to find out the solution. Thanks in advance</p>