"disk(s) are not visible cluster-wide"
*Cause: An ALTER DISKGROUP ADD DISK command specified a disk that could
not be discovered by one or more nodes in a RAC cluster
*Action: Determine which disks are causing the problem from the
GV$ASM_DISK fixed view. Check operating system permissions
for the device and the storage sub-system configuration on
each node in a RAC cluster that cannot identify the disk.