Oracle Solution for Error ora-15003

ORA-15003: diskgroup "string" already mounted in another lock name space

What triggered the Error:

The diskgroup could not be mounted by the ASM instance because it was operating in a lockspace different than another existing ASM instance which had already mounted the diskgroup.

What should we do to fix it:

Check the LOCK_NAME_SPACE initialization parameter value, or dismount the diskgroup from the other ASM instances.