ORA-27101 error: shared memory realm does not exist

An Oracle user asks why their machine is abnormally terminating and they are receiving the ORA-27101 error.

I have Windows 2000 server with Oracle 9i installed on it. Every day when an Oracle application is started on a client machine, it gives error 1034- 27101: shared memory realm does not exist. When I restart the Oracle server the problem is solved, but it occurs daily and I have to restart the server. Can you give me a permanent solution?
Your Oracle database instance is terminating for some reason. Rebooting the server simply causes the OracleServiceSID service to restart, thus restarting the Oracle instance. There could be many reasons why your Oracle instance is abnormally terminating. The only way to know for sure is to examine your Alert log for clues. There should be an error message there indicating why the instance is terminating, leading to the root cause.

For more solutions to common Oracle errors, check out our Solving common Oracle errors guide.

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