How to fix the Oracle error ORA-15291: ASM could not add disk “string” to disk group “string”?

In this post, you’ll learn more about the Oracle ErrorORA-15291: ASM could not add disk “string” to disk group “string” with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-15291: ASM could not add disk “string” to disk group “string”

Reason for the Error ORA-15291: ASM could not add disk “string” to disk group “string”

An attempt was made to add a disk to a disk group while the distribution of disks in failure groups was too uneven.

How to fix the Error ORA-15291: ASM could not add disk “string” to disk group “string” ?

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

Add or drop disks to or from failure groups to balance their distribution in all failure groups and retry the operation.