Ora-27100: shared memory realm already exists error Solution

Database ora-27100: solution to shared memory realm already exists errors

Environment:
Operating System Platform Windows Service 2003 R2 x86
Database Version: Oracle Enterprise 9.2.0.1 for windows x86

Today a customer database cannot start, reported ora-27100: shared memory realm already exists error. check related documents. errors are generally caused by improper memory parameter settings. the solution is to first create a pfile, modify the pfile parameters, save the modified parameters as the pfile file, then create a spfile, and restart oracle services.

Problem description: Database open error: ora-27100: shared memory realm already exists.
Problem diagnosis: The parameter file configuration is incorrect.

Process and steps for solving the problem

Environment:
Operating System Platform Windows Service 2003 R2 x86
Database Version: Oracle Enterprise 9.2.0.1 for windows x86

Today a customer database cannot start, reported ora-27100: shared memory realm already exists error. check related documents. errors are generally caused by improper memory parameter settings. the solution is to first create a pfile, modify the pfile parameters, save the modified parameters as the pfile file, then create a spfile, and restart oracle services.

Problem description: Database open error: ora-27100: shared memory realm already exists.
Problem diagnosis: The parameter file configuration is incorrect.

Process and steps for solving the problem

Solution 1,

1. Back up all parameter files, including spfile and pfile, to the desktop.
2. Execute create pfile from spfile in sqlplus.
3. Only the pfile File Created in step 2 is retained, and all others are deleted.
4. Use the UltrEdit tool to modify pfile. Note: The SGA size cannot exceed 1.7 GB, and other parts in the SGA cannot exceed the size configured in sga_max_size, the maximum unit size of the parameter used in 9i can only be M. My configuration is as follows:
Sga_max_size = 700 m
Db_cache_size = 400 m
Java_pool_size = 30 m
Large_pool_size = 80 m
Shared_pool_size = 150 m

5. Save and exit after modification, and check whether the file suffix is. ora.
6. Execute the create spfile from pfile command to create the spfile. Remember, never go to sqlplus and execute the starup to start the database.
7. Run the services. msc command in the cmd command to start the service manager, stop all oracle services, and change them to manual.
8. Restart the server
9. Manual oracle monitoring and instance services.
10. Use sqlplus to enter the database and execute select instance_name and status from v $ instance. The database status should be open.
11. Fault Handling is complete.