Examine the following command:
ALTER DISKGROUP data MOUNT FORCE;
In which scenario can you use the above command to mount the disk group?
A.
when ASM disk goes offline
B.
when one or more ASM files are dropped
C.
when some disks in a disk group are offline
D.
when some disks in a failure group for a disk group are rebalancing
Explanation:
In the FORCE mode, Oracle ASM attempts to mount the disk group even if it cannot
discover all of the devices that belong to the disk group. This setting is useful if some of the
disks in a normal or high redundancy disk group became unavailable while the disk group
was dismounted. When MOUNT FORCE succeeds, Oracle
ASM takes the missing disks offline.If Oracle ASM discovers all of the disks in the disk group, then MOUNT FORCE fails.
Therefore, use the MOUNT FORCE setting only if some disks are unavailable. Otherwise,
use NOFORCE.
In normal- and high-redundancy disk groups, disks from one failure group can be
unavailable and MOUNT FORCE will succeed. Also in high-redundancy disk groups, two
disks in two different failure groups can be unavailable and MOUNT FORCE will succeed.
Any other combination of unavailable disks causes the operation to fail, because Oracle
ASM cannot guarantee that a valid copy of all user data or metadata exists on the available
disks.
Refer to here