Processor Compatibility for vMotion

[Waleed_Akl]

My Customer has existing cluster with 4 blade servers (Intel Xeon E5-2670 2.6 Ghz 8 Core Processor) and want to add one more server in the same cluster. A partner has proposed Intel Xeon E7-2880v2 2.5 Ghz 15 Core Processor. Customer wanted to know: Is the vMotion possible between the 2 processor generations ? Will there be any compatibility issue having the 2 servers in same cluster ?

Thanks

[MKguy]

The Xeon E5-2670 is a Sandy Bridge generation CPU, while the Xeon E7-2880v2 is a slightly newer Ivy Bridge generation CPU.

Without EVC, vMotion of a VM that was powered-on on an Ivy Bridge host to a destination Sandy Bridge host will not be possible.

So just enable EVC on the cluster with the Sandy Bridge compatibility mode and you're fine in terms of vMotion compatibility. Also see:

VMware KB: Enhanced vMotion Compatibility (EVC) processor support

VMware KB: EVC and CPU Compatibility FAQ

[SavkoorSuhas]

Hello Waleed,

The E5-2670 is a Sandy Bridge family Intel processor.

The E7-2880 v2 is an Ivy Bridge family Intel processor.

The main rule in EVC is to set the lowest family as the baseline. In this case Sandy Bridge.

But, why?

Let's say Sandy Bridge has feature set of A, B and C

Ivy Bridge has feature set of A, B, C and D

Now a VM running on Ivy Bridge is actively using all the 4 feature sets. however, when migrated to the host having ABC feature sets, the VM panics and vMotion fails, why? Because it cannot find the feature set D.

So, by setting the lower family as EVC baseline you are masking the feature set D for the VM.

This obviously cannot be done when the VM is on, The VMs have to be powered off and then EVC enabled on the cluster with the required baseline. Because, if this is done online, the feature set D gets masked and the VM panics again.

For the best link to find the family of the CPU

http://www.virten.net/2013/04/intel-cpu-evc-matrix/