ORA-27101: shared memory realm does not exist


Sometimes You can get “ORA-27101: shared memory realm does not exist ” error.


Details of error are as follows.

ORA-27101: shared memory realm does not exist
Cause: Unable to locate shared memory realm
Action: Verify that the realm is accessible



This error is related with Invalid ORACLE_HOME and ORACLE_SID or  Database is  really down.


Check your ORACLE_HOME and ORACLE_SID with echo command, or if database is down start it up again as follows.

SQL> startup
ORACLE instance started.
Total System Global Area 1224736768 bytes
Fixed Size 1219112 bytes
Variable Size 167773656 bytes
Database Buffers 1040187392 bytes
Redo Buffers 15556608 bytes
Database mounted.
Database opened.



Do you want to learn Oracle Database for Beginners, then read the following articles.


About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

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