Which procedure would ensure the availability of a server with external access if the building loses power?

Implementing a UPS (Uninterruptible Power Supply) is essential for ensuring the availability of a server with external access during a power loss, especially in situations where immediate backup power is crucial. A UPS provides temporary battery power that allows servers to continue functioning seamlessly during short power outages, while also offering essential surge protection to prevent potential damage from power spikes. This immediate response ensures that critical operations remain uninterrupted, allowing for a smooth transition to longer-term solutions if power restoration is delayed.

While a secondary power source can enhance server reliability, it may not offer the immediate, short-term support that a UPS provides during unexpected outages. Redundancy with multiple servers primarily addresses issues related to load balancing and failover, but it does not directly resolve power availability during an outage. Lastly, using a generator is useful for long-term outages but may require time to fully engage and isn't as effective for short-duration power failures. The UPS stands out as the best choice for maintaining server functionality in the event of a sudden power loss.