Currently running into a weird EVC problem with one test environment we've set up. Bear with me, it may be a bit long to read.
We are in the process of testing vSphere 4, currently focusing on its support of legacy hardware and ESXi servers we have in preparation for a migration.
Our environment is as follows :
1 vCenter 4 server (upgraded from a VC 2.5 u5 installation if its relevant)
1 HP BL460c G1 blade with E5430 CPU (Penryn), running ESXi 3.5 build 176894 (that's u4 with the july 2009 firmware update)
1 HP BL460c G6 blade with E5520 CPU (Nehalem) running ESXi 4.0.0 build 164009
1 HP BL460c G6 blade with E5520 CPU (Nehalem) running ESXi 3.5u4 (original build, no fix).
The three ESX servers are part of an EVC enabled cluster, using the "Core 2" baseline (the most compatible). EVC was enabled without error or warning at the cluster level and each server in the "summary" tab of the VI client report EVC is OK.
All ESXi images are the HP provided OEM image. DNS has been thouroughly tested and is OK.
I've got three VMs running, one started on each server, to test various migration scenarii. The weirdness starts here.
I CAN migrate the VM which was started on the ESXi 4 server to the two others, and back, without no problem.
I CANNOT migrate the VM on the ESXi 3.5 / BL460c G1 to any other server.
I CANNOT migrate the VM on the ESXi 3.5 / BL460c G6 to any other server.
However, if I take out the two ESXi 3.5 servers and add them into an EVC enabled cluster on a VirtualCenter 2.5 (update 5), and try a VMotion, then all goes well.
Now some more weirdness. I did re-add the ESXi 3.5 servers into the vCenter 4 server and apply the same level of hotfix to the second server through UM, now both are running build 176894. The following situation occurs :
I STILL CAN migrate the VM which was started on the ESXi 4 server to the two others (and back) without no problem.
I NOW CAN migrate any VM started on any ESXi 3.5 server to the second one (so from Penryn to Nehalem).
I STILL CANNOT migrate any VM started on any ESXi 3.5 server to the ESXi 4 server.
So it seems EVC works -- partially, and in any case, not between ESXi servers of different releases. Any thoughts ?
oops, got carried away describing the setup and forgot to mention that, you're right.
I actually get a CPU mismatch error, ecx register error and feature not supported. Which would be expected between Penryn and Nehalem if EVC wasn't enabled.