Benefits and cons of EVC mode

Deathmage

Hey guys,

what would be the benefit of having EVC mode for a cluster on Sandy Bridge if the Xeon's are not Sandy Bridge but Nehalem?

Like what does the emulation do really?

Here is what I set it too:



Here is what the Xeon's are:

Essendon

EVC in simple terms is the dumbing down of the CPU features to present a homogeneous architecture to all VMs so as to ensure vMotion compatibility across all hosts in the cluster. The only con, and it's not a con really, is the very slight administrative overhead of choosing the right mode. There's really no con I can think of. Only thing is this, VMs must be powered off for it take effect.

iBrokeIT

Deathmage wrote: »

what would be the benefit of having EVC mode for a cluster on Sandy Bridge if the Xeon's are not Sandy Bridge but Nehalem?

Your wording is a bit ambiguous so I'll discuss all options.

If both physical CPUs are Nehalem then you can not run EVC mode: Sandy Bridge because that is a higher EVC mode with CPU features that were created after Nehalem was released.

If both physical CPUs are Sandy Bridge then you would have every EVC mode at Sandy Bridge and below available to set including Nehalem.

If one physical CPU is Sandy Bridge and the other is Nehalem then only the lowest common EVC mode would be available which would be Nehalem.


VMware KB: Enhanced vMotion Compatibility (EVC) processor support

Deathmage

Koodos! - thanks!