How to fix the Oracle error ORA-15404: Oracle ASM could not add disk “string” to disk group “string” on appliance string?

In this post, you’ll learn more about the Oracle ErrorORA-15404: Oracle ASM could not add disk “string” to disk group “string” on appliance string with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-15404: Oracle ASM could not add disk “string” to disk group “string” on appliance string

Reason for the Error ORA-15404: Oracle ASM could not add disk “string” to disk group “string” on appliance string

There were too many dropping or offline disks in the specified disk group.

How to fix the Error ORA-15404: Oracle ASM could not add disk “string” to disk group “string” on appliance string ?

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

Wait for the drop and rebalance operations to complete, or online the offline disks and wait for the online to complete. Then, retry the operation.