vMotion everybody knows. Right? If not your are living under the rock….. -:) Just kidding. Using vMotion you can move the VMs needed to another host (another physical server) in your cluster. For what? Like this you can stop your physical server for maintenance, cleaning, vacuum cleaning…..of course. Even the serves needs some vacuum cleaning….
But what is EVC ? (Enhanced vMotion capapility). First I thought that it is some kind of better vMotion cool stuff, or so. But then I found this KB on VMware Website:
Enhanced VMotion Compatibility (EVC) simplifies VMotion compatibility issues across CPU generations. EVC automatically configures server CPUs with Intel FlexMigration or AMD-V Extended Migration technologies to be compatible with older servers. After EVC is enabled for a cluster in the VirtualCenter inventory, all hosts in that cluster are configured to present identical CPU features and ensure CPU compatibility for VMotion. The features presented by each host are determined by selecting a predefined EVC baseline. VirtualCenter does not permit the addition of hosts that cannot be automatically configured to be compatible with the EVC baseline.
And also this:
To use the EVC feature, you must be running ESX Server 3.5 Update 2 or higher with Virtual Center 2.5 Update 2 or higher and have only compatible processors that are listed in one of the following tables. EVC does not allow for migration with VMotion between Intel and AMD processors.
So with this in my mind I went to Rich Bramley's blog.
Basicaly all your hosts in your cluster does not has to be fully compatible with vMotion and you still has the possibility to use the vMotion if you go to the advanced features and you enable EVC.
There is also a PDF paper from DELL : VMware VMotion and 64-bit VM Compatibility Matrix for VMware Infrastructure 3 and Dell PowerEdge Systems contains a VMotion and 32/64-Bit VM Compatibility Across Processor Models. And from HP too.
See the original KB from VMware here: https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003212