The vmx file is the file used as a value dictionary that provides the configuration of the virtual machine. The per-EVC configuration is saved in the vmx file. When a virtual machine is powered off, you can change the per-VM EVC baseline. Virtual machine hardware version 14 or up is required to enable per-VM EVC. We introduced the per-VM EVC feature in vSphere 6.7. This helps to be more flexible with EVC enablement and baselines.

Next to that, it is challenging to change a cluster EVC baseline in a environment with live workloads.īy implementing per-VM EVC, the EVC mode becomes an attribute of the virtual machine rather than the specific processor generation it happens to be booted on in the cluster. When a virtual machine is moved to another cluster, either on-prem or in a hybrid cloud environment, it loses its EVC configuration depending on the destination environment.

Per-VM EVCĮVC is a cluster level setting that supports virtual machine mobility within a cluster. This VMware KB article goes into more detail about all current EVC baselines and what CPU instructions they expose to the virtual machines. When EVC is enabled on the cluster, all ESXi hosts in the cluster must adhere to that setting. It allows EVC to learn what instruction-sets the CPU is capable of doing, and what instructions needs to be masked depending on the configured EVC baseline. Basically, you can look at the CPUID being an API for the CPU. By doing so, EVC ensures that all virtual machines in the cluster are running on the same CPU instructions allowing for virtual machines to be live migrated (vMotion) between the ESXi hosts.ĮVC determines what instructions to mask from the guest OS by using the CPUID. If you would add a newer host to the cluster, containing newer CPU packages, EVC would potentially hide the new CPU instructions to the virtual machines. That means EVC will allow and expose CPU instruction-sets to the virtual machines depending on the chosen and supported compatibility level. The way EVC allows for uniform vMotion compatibility, is by enforcing a CPUID (instruction) baseline for the virtual machines running on the ESXi hosts. This blog post will go into details about EVC and the per-VM EVC feature. That’s why we stress to have it enabled from the get-go. To enable EVC in a brownfield scenario can be challenging.

VSphere Enhanced vMotion Compatibility (EVC) ensures that workloads can be live migrated, using vMotion, between ESXi hosts in a cluster that are running different CPU generations. The general recommendation is to have EVC enabled as it will help you in the future where you’ll be scaling your clusters with new hosts that might contain new CPU models.

Vmware esxi 6.7 compatibility