Which components are included in dual or quad engine setups but not in a single engine?

In dual or quad engine setups, additional components are included to enhance redundancy, reliability, and performance in comparison to a single engine setup. Specifically, the correct answer emphasizes that in configurations with multiple engines, there are two Fibre Channel (FC) switches, two uninterruptible power supplies (UPS), and a management server.

The inclusion of two FC switches is crucial for creating a resilient architecture to manage storage traffic effectively, allowing seamless failover capabilities and load balancing between the engines. This ensures that if one switch experiences issues, the other can take over without disrupting operations.

Moreover, having two UPS systems ensures continuous power supply under various conditions, adding another layer of fault tolerance. This is particularly important in environments where uptime is critical.

The management server plays a vital role in overseeing the operation of multiple engines, providing a centralized point of control and monitoring, which is especially beneficial in a setup where several engines can complicate configuration and management tasks.

Overall, the components specified in the correct answer support the enhanced functionality and reliability of dual and quad engine configurations, which are essential in enterprise environments where high availability and performance are paramount.