ORA-15201: disk string contains a valid RDBMS

admin

ORA-15201: disk string containsa valid RDBMS file
Cause: A disk specified in a CREATE DISKGROUP or ALTERDISKGROUP ...
ADD DISK command appeared to contain a file from an existing database. By
default, ASM will not allow a diskgroup to be created using this disk, as a
safeguard against damaging an existing database.
Action: Checkthat the ASM disk specification is correct. Otherwise, when storage
from a defunct database is reused as part of an ASM diskgroup, specify the
FORCE option to the ASM SQL command.