How to fix the Oracle error ORA-15055: unable to connect to ASM instance?

In this post, you’ll learn more about the Oracle ErrorORA-15055: unable to connect to ASM instance with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-15055: unable to connect to ASM instance

Reason for the Error ORA-15055: unable to connect to ASM instance

The RDBMS instance was unable to connect to the required ASM instance when accessing a disk group.

How to fix the Error ORA-15055: unable to connect to ASM instance ?

You can fix this error in Oracle by following the below steps

Check the additional error messages. May need to configure correct ASM sid or make sure the RDBMS instance has OS privileges for ASM SYSDBA.