What are EVC and its purpose in VMware vSphere?

The purpose of Enhanced vMotion Compatibility (EVC) in VMware vSphere is to provide enhanced compatibility across different CPU generations within a cluster. EVC allows virtual machines (VMs) to be migrated seamlessly between hosts with different CPU types or architectures without compatibility issues. This is particularly important in environments where hardware may be upgraded over time. EVC ensures that the guest operating system and applications running inside the VMs can operate without problems, regardless of the underlying physical CPU variations.

By enabling EVC, vSphere standardizes the CPU feature set presented to the virtual machines. It masks CPU features that are not present on all hosts in the cluster, allowing for safe live migrations (vMotion) regardless of the specific CPU models or the generation of the processors being used. This enhances the flexibility and operational continuity in a virtualized environment, allowing administrators to perform maintenance and upgrades without downtime for the VMs.