CMMVC5810EThe quorum index number for the managed disk (MDisk) was not set because the MDisk is not available, either because the MDisk is offline or because it is associated with another quorum disk.
Explanation
The MDisk that you specify for this task must be online and cannot already be a quorum disk.
Action
Either change the status of the MDisk to online or specify a different MDisk, and resubmit the command.