EVC Mode

[kevin79]

I am trying to enable EVC mode on a cluster but get the message "The host cannot be admitted to the cluster's current Enhanced vMotion Compatibily mode. Powered-on or suspended virtual machines on the host may be using CPU features hidden by the mode.".

The cluster originally had 2 Dell PowerEdge R810 servers with dual Intel Xeon E7540 cpu's. I'm trying to add 2 older Dell PowerEdge R900 servers that have quad Intel Xeon E7320 cpu's. I'm guessing it won't let me enable it because the powered on virtual machines are using the newer servers (R810) and their cpu's. Is my guess correct? Do I have to power off all of my VM's in order to enable EVC or is there another way to enable it?

[julienvarela · Accepted solution]

Hi,

Yes your guess was correct. You need to power off all your VMs for enable EVC mode.

More informations about enabling EVC : VMware KB: Enabling EVC on a cluster when vCenter is running in a virtual machine

Regards,

Julien

[a_p_]

Yes, if EVC would allow the hosts to join the cluster, any VM which you vMotion to one of the hosts with the lower feature set would most likely crash. If you don't want to power off all VMs at the same time, you may create a new cluster with the new hosts, configure the required EVC mode and migrate the VMs one-by-one. Once all VMs are migrated move the hosts to the new cluster and delete the old one. Whether this is an option in your case, may depend on the cluster features used and any third party tools!?

André

[kevin79]

Thanks guys.