Exam 2V0-21.23 topic 1 question 86 discussion

C You would enable EVC on the existing cluster as skylake, all the VMs are already using skylake so they would be able to move to the New hosts ok. If you create a new cluster you have to put the hosts in Maint mode when moving between clusters.

From the lecture manual: To activate EVC on an existing cluster, all hosts must be placed in maintenance mode, and therefore all VMs in the existing cluster must be powered off or suspended. To avoid VM downtime, the recommended method for activating EVC is to activate this feature on a new, empty cluster.

C There is no virtual machine downtime during the process of adding the new hosts

I go with C. You can enable EVC on a Cluster at a max EVC Level what your Hosts can provide. But you have to enable EVC before adding the new Hosts!

https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vcenterhost.doc/GUID-E3F5BAFE-EB14-408D-999A-590D4337D59C.html You must power off all powered on virtual machine with no EVC mode or with an EVC mode that is greater than the EVC mode that you plan to enable on the cluster. As existing VMs are not having EVC enabled yet.. option C would imply to stop all VMs. So, going for option A

The administrator must ensure that: • There is no virtual machine downtime during the process of adding the new hosts. Enable EVC on an Existing Cluster "Power off all the virtual machines on the hosts with feature sets greater than the EVC mode." https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vcenterhost.doc/GUID-E3F5BAFE-EB14-408D-999A-590D4337D59C.html

Answer: C The Cluster is using older hardware (Skylake). VM's that have been created in this cluster will be using the CPU features of this hardware. Enabling EVC mode that is supported by Skylake will then limit the CPU features presented to the VM's when the IceLake Hardware is added to the cluster, thereby not requiring the VM's to be powered off. If you were adding older CPU Hardware to a cluster with newer CPU hardware, then this will require the VM's to be powered off and EVC Mode set to a lower level for the cluster. When the VM's power back on, they are then only aware of the EVC CPU feature set enabled which will allow the VM's to live migrate to the older hardware. To Simplify. 1. Newer Hardware added to Cluster with older hardware = Enable EVC Mode Enabled and Set, No VM Downtime. 2. Older Hardware added to Cluster with Newer Hardware = VM's to be powered off, EVC Enabled and Set, VM's powered on

Answer is A because no downtime is required You can use one of the following methods to create an Enhanced vMotion Compatibility cluster: • Create an empty cluster with EVC mode configured and move hosts into the cluster. • Configure EVC mode on an existing cluster. To activate EVC on an existing cluster, all hosts must be placed in maintenance mode, and therefore all VMs in the existing cluster must be powered off or suspended. To avoid VM downtime, the recommended method for activating EVC is to activate this feature on a new, empty cluster. For information about Enhanced vMotion Compatibility processor support, see VMware knowledge base article 1003212 at http://kb.vmware.com/kb/1003212.

You would enable EVC on the existing cluster as skylake

Just tested in my 8.x lab with 4 hosts. I can disable and enable EVC at will without powering off VMs. You need to ensure that you select the correct EVC mode (the precheck will warn you if you are on the wrong mode), and it will enable.

Trick question... It specifically says "into an existing production vSphere cluster" meaning that creating a new cluster is not within this scenario. Also "no virtual machine downtime DURING the process of ADDING the new hosts" which says to me that there could be scheduled downtime for the vms at a later date/change window. From the study guide... "Be aware when changing EVC in a Cluster, a VM does not use the new feature set until it is powered-off then back on, not restarted" So, you configure evc on the existing cluster and add the new hosts to the cluster. At a later date/change window, you power off the vms and power them back on to get EVC functionality. That's my take anyway.

Answer C : the VMs already on the existing cluster will have EVC automatically activated as the CPUs are Skylake processors. So the cluster EVC configuration can be modified without having to power off the VMs or putting any host in maintenance (tested a few minutes ago).

I would go with A because that would have the least amount of down time. C would mean you have to power down all the VMs running on the cluster.

A - Tested in a lab with the newest version and C didn't work.

You can use the Enhanced vMotion Compatibility (EVC) feature to help ensure vMotion compatibility for the hosts in a cluster. EVC ensures that all hosts in a cluster present the same CPU feature set to virtual machines, even if the actual CPUs on the hosts differ. Using EVC prevents migrations with vMotion from failing because of incompatible CPU https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vcenterhost.doc/GUID-9F444D9B-44A0-4967-8C07-693C6B40278A.html

The correct answer is: C. Configure Enhanced vMotion Compatibility (EVC) mode on the existing cluster and add the two new hosts into the cluster.

Creating a new cluster (options A and D) isn't necessary and would require migrating virtual machines between clusters, which could cause downtime. Option B, moving only three hosts, doesn't ensure that any virtual machine can migrate to any host in the cluster, which doesn't meet the requirement given.