Redundant storage controllers are included. This configuration has no single point of failure. Dual porting and volume shadowing provide multiple copies of essential disks across separate HSJ controllers. All nodes have shared, direct access to all storage. A quorum disk allows other node to continue if one node fails.
All nodes have direct access to storage.
CI is inherently dual pathed. No single component failure can disable the cluster. Redundant storage controllers can be used to provide additional performance by dividing disks between the two storage controllers. 1 Critical disks are shadowed with shadow set members on different SCSI buses. Second CI adapter in each host is unlikely to enhance performance.