Enhanced VMotion Compatibility (EVC) processor support

[max2479]

Hi all,

I have 4 hosts that have different Intel processors.

esx1 - 54xx

esx2 - 54xx

esx3 - 55xx

esx4 - 56xx

VMotion is not working for me until I enable EVC on my cluster. But to enable it, VMware tells me I have to shutdown all my VMs on all ESX hosts to enable it on the cluster. Is this correct? do I have any other work around or back door to enable EVC?

[FranckRookie]

Hi Max,

No, there is no other way. When enabling EVC, vCenter will apply a CPU mask to all VMs on the cluster. And this mask needs the VM to be restarted for the change to be taken into account.

Sorry.

Regards

Franck

[AndreTheGiant]

The only other way is manually mask CPU feature to each VM.

But EVC is more simple.

To enable it without downtime:

http://communities.vmware.com/thread/201677

[max2479]

Andre,

The workaround was to put the host into a maintenance mode...

Putting host to maintenance mode need migration of VMs from that host.

This is not going to work as VMotion is having issue due CPU incompatibility.

I can't afford to down all my VMs unfortunatelty.... How about If I use FT option to migrate them to another host? or FT requires vmotion thus compatible CPU or EVC enabled?

[AndreTheGiant]

FT need vMotion compatibility.

If you add a old CPU then there is no solution.

But when you add a new host with a recent CPU the solution is to put it in a new EVC cluster to "downgrade" the CPU.

At this point you can do vMotion and free the other nodes.

Andre

[bulletprooffool]

Max,

The way to approach this is to create a new empty cluster and enable the correct level of EVC on this.

Get one of your hosts added to the cluster (odds are you'll need to evacuate your VMs)

Now, each time you have a reboot scheduled for a VM, move it to the new 'cluster' until you get to a point where you can free up a second host.

At this point, again add it to the cluster (now EVC is on the host)  and continue the process.

For me, the easiest time to enable EVC (though I almost always try avoid it) is during our monthly Microsoft Patch run - as we have down time for all servers anyway. We start our patch runs with a reboot, so when enabling EVC, I simply shut them down, enable EVC and start them all up (but of course this only applies if VMs that are on the host are patch ed as similar intervals.)

Good luck