What capability provides protection against unexpected hardware or power supply failures?

The capability that offers protection against unexpected hardware or power supply failures is a Fault Domain. In Oracle Cloud Infrastructure, Fault Domains are designed to provide high availability and reliability by mitigating risks associated with hardware failures. A Fault Domain is essentially a grouping of hardware and underlying resources that are isolated from other Fault Domains in the same region. This means that if one Fault Domain experiences a failure, the workloads running in other Fault Domains remain unaffected.

This method of isolation ensures that applications can continue to operate even if a specific hardware failure occurs in one of the Fault Domains. By distributing resources across multiple Fault Domains, users can enhance the resiliency of their applications and services against potential outages, whether due to hardware failures, power supply issues, or other unforeseen circumstances.

Other options, such as Compartments, relate more to resource management and access control rather than direct hardware resilience. Lots of back switches and Power Distribution Units are more relevant to physical infrastructure management and do not specifically provide the abstraction layer needed for managing fault tolerance within cloud environments. Thus, the Fault Domain is the key component in OCI for ensuring that applications remain operational despite hardware-related issues.