Exchange clusters are browsed and managed in the same way as any individual Exchange servers (in the Microsoft Exchange servers view of the management server).
You manage a cluster as a whole rather than as a set of nodes. When selecting the cluster data for backup (or browsing cluster data in the Data view), the data is displayed as a single instance even if multiple copies of the data are available within the cluster.
Availability of the management server
The management server's availability is mandatory for creating and editing the centralized backup plans, since the management server deploys the backup plan to every node of the cluster. However, its availability is not necessary to run backup and recovery tasks.