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VMware EVC Mode Enabling Error in Nutanix vSphere Cluster

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VMware HCI - EVC Mode Error Troubleshooting

Nutanix HCI - VMware EVC Mode Error Troubleshooting

In Nutanix HCI deployed with VMware vSphere ESXi cluster configured at virtualization layer, in new installation and/or during the expanding with Nutanix node i.e G4, G5, G6, G7, G..x..n nodes in existing Nutanix vSphere cluster, generally face the error to enabling the VMware vSphere EVC ( Enhanded vMotion Compatibility ) mode you might got following error in VMware EVC Mode Enabling Error in Nutanix vSphere Cluster as mentioned below:

VMware EVC Error 1: The host’s CPU hardware should support the cluster’s current Enhanced VMotion Compatibility mode, but some of the necessary CPU features are missing from the host. Check the host’s BIOS configuration to ensure that no necessary features are disabled (such as XD, VT, AES, or PCLMULQDQ for Intel, or NX for AMD). For more information, see KB articles 1003212 and 1034926.

MVware EVC Error 2: vMotion / EVC incompatibility issues due to AES / PCLMULQDQ

VMware EVC Error 3: The host cannot be admitted to the cluster’s current Enhanced vMotion Compatibility mode. Powered-on or suspended virtual machines on the host may be using CPU features hidden by that mode.

I have described the VMware vSphere EVC error reason and solution as well in this blog. Lets go to to depth of the solution.

Read also: Nutanix Move Migration Guide ?

What is VMware vSphere EVC ?

VMware vSphere EVC is short for Enhanced vMotion Compatibility. EVC allows you to migrate virtual machines between different generations of CPUs. EVC is enabled for a cluster in the VirtualCenter / vCenter Server inventory. After it is enabled, EVC ensures that migration with vMotion is possible between any hosts in the cluster. Only hosts that preserve this property can be added to the cluster.

VMware vSphere EVC: Enhanced vMotion Compatibility allows you to migrate virtual machines between different generations of CPUs, with EVC you can mix older and newer server generations in the same cluster and be able to migrate virtual machines with vMotion between these hosts.

This makes adding new hardware into your existing infrastructure easier and helps extend the value of your existing hosts. With EVC, full cluster upgrades can be achieved with no virtual machine downtime whatsoever. As you add new hosts to the cluster, you can migrate your virtual machines to the new hosts and retire the older hosts.

How VMware vSphere EVC Works ?

How VMware EVC Mode Works

VMware vSphere EVC: Enhanced vMotion Compatibility is enabled for a cluster in the VirtualCenter or vCenter Server inventory. After it is enabled, EVC ensures that migration with vMotion is possible between any hosts in the cluster. Only hosts that preserve this property can be added to the cluster.

After VMware vSphere EVC Enhanced vMotion Compatibility is enabled, all hosts in the cluster are configured to present the CPU features of a user-selected processor type to all virtual machines running in the cluster.

This ensures CPU compatibility for vMotion even though the underlying hardware might be different from host to host. Identical CPU features are exposed to virtual machines regardless of which host they are running on, so that the virtual machines can migrate between any hosts in cluster.

Read also: Cross Hypervisor Migration To-from Nutanix AHV

Can migrations with vMotion still fail for virtual machines within an EVC cluster?

Yes. More factors than CPU compatibility are used to determine vMotion compatibility. For example, if the virtual machine does not reside on storage shared by the source and destination hosts, then migration with vMotion cannot occur between these hosts.

Does EVC allow AMD and Intel CPUs to be vMotion compatible?

No. An EVC-enabled cluster only allows CPUs from a single vendor in the cluster. VirtualCenter and vCenter Server do not allow you to add a host from a different CPU vendor into an EVC-enabled cluster.

Mixing nodes with different processor (CPU) types in the same cluster

If you are mixing nodes with different processor (CPU) types in the same cluster, you must enable Enhanced vMotion Compatibility (EVC) to allow vMotion/live migration of VMs during the hypervisor upgrade.

For example, if your cluster includes a node with a Haswell CPU and other nodes with Broadwell CPUs, open vCenter and enable VMware Enhanced vMotion Compatibility (EVC) setting and specifically enable EVC for Intel Hosts.

Read also: Nutanix Cluster Most Critical Services

VMware vSphere EVC Compatability Factor

VMware vSphere EVC ( Enhanced vMotion Compatibility ) capabilities of your server are based on two factors:

  1. The vCenter Server version that manages the host.
  2. The underlying CPU manufacturer & architecture of the host processor.

You may run into this issue while enabling VMware EVC with below configurations:

Host with ESXi 6.5 U2b 8935087 (Nutanix G4 node) moving to the cluster at ESXi 6.5 U2c (Nutanix G5 node) with the baseline of Intel “Haswell” generation. Read more: VMware Esxi 6.5 U1 High CPU Consumption issue

Validated required vCenter / Spectre Meltdown patches / Required BIOS settings but issue resolved after applying the latest ESXi 6.5 patch and able to move the Nutanix G4 node to the cluster without any EVC error message.

Read also: Nutanix AHV: Enable VLAN Trunk Mode on Guest VM

Supported Processors for VMware EVC feature:

Note: The following list might change to include more supported processors. Refer to the VMware documentation for an updated list.

Please refer the following comparability before enabling the VMware EVC mode.

ESXi 5.5 supports these EVC modes:

Read also: Nutanix End of Life Announcement VMware vSphere 5.5

ESXi 6.0 supports these EVC modes:

ESXi 6.5 supports these EVC modes:

Read also: Nutanix Security Advisory Intel CPU Vulnerability MDS

ESXi 6.7 supports these EVC modes:

Read also: Nutanix In-Place Hypervisor Conversion | ESXi – AHV

AMD EVC Baselines supported in vCenter Server releases

AMD EVC Baselines supported in vCenter Server

Intel EVC Baselines supported in vCenter Server releases

Intel EVC Baselines supported in vCenter Server

VMware Reference KB list:

Conclusion

VMware EVC ( Enhanced vMotion Compatability ) error is common in VMware vsphere because EVC mode depends on the two factors known as VMware vSphere vCenter server version and CPU manufacturer, generation, Model and version. Nutanix supports VMware virtualization layer in Nutanix HCI cloud enabled stack.

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