ORA-00821: Specified value of sga_target 5120M is too small, needs to be at least 12352M

There could be situations where you are trying to start your database instance, however, it returns an error message instead of starting up. Such errors are mostly related to init parameters and must be fixed before retrying to start the instance. Issue could be related to an invalid value of a parameter or syntax error in the parameter file. In the following I will explain one of the errors that are related to an invalid value of parameter SGA_TARGET.

SQL> startup nomount pfile=initaux.ora  ORA-00821: Specified value of sga_target 5120M is too small, needs to be at least 12352M  ORA-01078: failure in processing system parameters  SQL> exit

If you are trying to startup an instance and it returns message ORA-00821, this clearly means the SGA size in insufficient and you must increase the value of SGA to at least the size advised in the message. In above example, advice is to set SGA_TARGET to at least 1235M. I set it to 13G and was able to start the instance.