What is a requirement to use the PowerProtect DD HA feature?

A PowerProtect DD High Availability (HA) configuration is designed for resilience against controller failure. It consists of two controller nodes, one active and one standby, which are connected to a single, shared set of storage shelves. If the active node fails, the standby node takes over and mounts the shared file system, ensuring data access continuity. This architecture relies on a single storage pool that both nodes can access, rather than duplicating the storage itself, which would be a replication or disaster recovery solution, not HA.

A. Each head unit having its own shelf is a standard, non-HA configuration and would not allow for failover to shared storage.
B. PowerProtect DD HA operates in an active/standby (or active/passive) configuration, not active/active, where only one node is active at any time.
D. A dual set of shared storage is not the architecture for DD HA; it implies data replication, which is a different data protection strategy.

1. Dell PowerProtect DD Series Version 7.7 High Availability Configuration Guide, Page 8, "HA configuration overview". The document states, "A PowerProtect DD HA configuration consists of two interconnected nodes that share storage."

2. Dell PowerProtect DD Series Concepts and Features Guide, "High Availability" chapter. It describes the architecture as two nodes sharing a common set of storage shelves.