alainap84
Contributor
Contributor

VMotion VM's between EVC modes

Hi. I have a VM that is currently sitting in a different cluster. This cluster is running EVC mode "Sandy Bridge." I need to migrate it to a cluster of 12 host that are running EVC mode "Meron." I get an error when trying to vmotion due to features being disabled. Can I change the EVC mode? If so, what impact would this have?

0 Kudos
10 Replies
daphnissov
Immortal
Immortal

You cannot change the EVC mode to something more restrictive than the current setting without having all VMs on the cluster powered off.

0 Kudos
alainap84
Contributor
Contributor

If I read the compatibility chart correctly, it looks like "Merom" EVC is more restrictive than the "Sandy Bridge."? If I am going from Merom to Sandy Bridge, wouldn't I be upgrading?

0 Kudos
sjesse
Leadership
Leadership

EVC effects what cpu instructions are available to the vm when its turned on., which is why you get the error you are seeing, since the running vms don't have those instructions exposed. It works the other way because the newer cpus still have the same as the older ones still. All  EVC reall does is hides the newer cpu instruction sets.

0 Kudos
alainap84
Contributor
Contributor

I have about 2,500 VM's running in a 12 host cluster with EVC mode "Meron"

I have 1 VM running in a 3 node cluster with EVC mode "Sandy Bridge."

I need to get that 1 VM to the other cluster running "Meron." What would be my best option here?

0 Kudos
sjesse
Leadership
Leadership

You have no other option other then turning the server off and migrating it then turning it on again.

0 Kudos
alainap84
Contributor
Contributor

Do you mean shutting down the VM and migrating it?

0 Kudos
sjesse
Leadership
Leadership

Yes

0 Kudos
alainap84
Contributor
Contributor

It's my vcenter server. If I power it off, I can't vmotion it. I know I can manage it from the host its currently sitting on, but not vmotion.

0 Kudos
sjesse
Leadership
Leadership

You need to connect directly to the host its on, shut it down, remove it from inventory and then go to the other host and find it in the datastore its stored in and add it to the inventory again. The have an article about enabling evc that talks about doing the same thing

VMware Knowledge Base 

0 Kudos
Arthos
Enthusiast
Enthusiast

Hello alainap84 ,

For migrating between different EVC types I would recommend using per VM EVC which is available from vsphere 6.7 onwards.

-If it helps , consider marking it as helpful.

0 Kudos