Startup Fails With ORA-27100 After Restarting The Windows Service

(Doc ID 370469.1)

Last updated on DECEMBER 06, 2016

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 9.2 to 11.2]
z*OBSOLETE: Microsoft Windows Server 2003


ORA-27100 is reported during a manual startup of the database .

C:\> sqlplus / as sysdba
SQL*Plus: Release - Production on Mon Dec 19 09:29:20 2011
Copyright (c) 1982, 2007, Oracle. All Rights Reserved.

Connected to an idle instance.

SQL> startup
ORA-27100: shared memory realm already exists

SQL> shutdown immediate
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist

Restarting the service, the same error is encountered.
Rebooting the server does not help as well (because that also restarts the service).


The parameter sga_max_size was increased, e.g. from 2GB to 3GB.


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