Why might an administrator fail to configure EVC on a cluster containing both AMD and Intel hosts?

Enabling Enhanced vMotion Compatibility (EVC) on a cluster that contains both AMD and Intel hosts requires careful consideration of the processor types. Each processor type has different architectural features and capabilities, which can lead to compatibility issues during virtual machine vMotion operations.

The correct answer highlights the importance of segregating hosts by processor type before enabling EVC because EVC is designed to ensure that all ESXi hosts in a cluster present a consistent CPU feature set to the virtual machines. This consistency allows VMs to be migrated seamlessly. When you have mixed processor types—AMD and Intel—the EVC mode must be chosen based only on the least capable feature set from both types. If the CPU features are not taken into account and a mixed environment is used without the necessary segregation, the cluster might not be validated for EVC, resulting in a failure to configure it.

Options involving vMotion configuration, passthrough devices, or vSphere HA setup may relate to cluster operations but are not directly related to the fundamental requirement of matching processor types in the EVC setup. These factors do not address the core issue of CPU feature compatibility, which is critical in a mixed-processor environment.