In this post, you’ll learn more about the Oracle ErrorORA-15416: ASM disk string in disk group string is offline. with the details on why you receive this error and the possible solution to fix it.
Oracle Error Description
ORA-15416: ASM disk string in disk group string is offline.
Reason for the Error ORA-15416: ASM disk string in disk group string is offline.
An offline disk prevented the current ADD or DROP operation.
How to fix the Error ORA-15416: ASM disk string in disk group string is offline. ?
You can fix this error in Oracle by following the below steps
Drop the offline disk or online the offline disk or disable appliance mode.