High availability in a storage environment implies that:

Using a single instance of each component directly contradicts the principle of high availability, as it creates numerous single points of failure.

RAID-0 provides performance benefits through striping but offers no data redundancy and does not contribute to the high availability of the overall storage system components.

Using a single controller in all arrays introduces a critical single point of failure; if that controller fails, all connected arrays become inaccessible, undermining high availability.

High availability aims to eliminate single points of failure by implementing redundancy across all critical components, such as power supplies, controllers, network paths, and storage devices. This ensures that if one component fails, another redundant component can immediately take over, preventing service interruption and maintaining service uptime.