ORA-01081: cannot start already-running ORACLE – shut it down first

ORA-01081: cannot start already-running ORACLE – shut it down first

This error is observed when you try to start already started instance

SQL> startup nomount;
ORACLE instance started.

Total System Global Area 1577058304 bytes
Fixed Size                  2924832 bytes
Variable Size            1157631712 bytes
Database Buffers          402653184 bytes
Redo Buffers               13848576 bytes

Already the database instance is up

SQL> startup nomount;
ORA-01081: cannot start already-running ORACLE - shut it down first

Shutdown the database and then try –Warning – use this command with caution. Think twice before execute the statement in production

SQL> shutdown immediate;