A few differences that prevent VMotion without a proper masking are:

AMD Opteron K8 (single core 1xx,2xx,8xx):
3DNow, SSE, SSE2, AMD64

AMD Opteron K9 (dual core 2xx,8xx and 22xx,82xx):
Same as K8 plus Cool+Quiet, SSE3, NX, AMD-V
This should be the ones you were referring to

Opteron K10 (Barcelona) (quad core 23xx,83xx):
Same as K9 plus Extended 3Dnow, SSE4a, NPT

Yep, that's what I would do as well.

Just wondering if you ever got more information on this. I'm in the same boat with server replacements. I've setup a new cluster, but not by choice. I'm running HP DL385 G1, BL465c G1 and now BL465c G5 servers with Opteron 285 dual cores, 2220 Duals and 2356 quads. I got vmotion working between the DL385s and BL465cG1s but haven't gotten a cpu mask to work with the quads.

Bill S.

Did you make the changes to the Virtual Machine Default CPU mask or on the AMD Override?

Bill S.

Anders:

Thanks you very much for the CPU masks. I've just tried them on a test system and they seem to work well. I realize that they turn off features but I suspect many of the VMs running on my hosts aren't using those features to any great benefit anyway. Now if I can just find a way to modify 300 VMs...

Bill S.

I would recommend using the perl vi toolkit (I'm a powershell guy myself), but with perl and the http://<fqdn of virtualcenter>/mod, you should have everything you need to script the changes. Some changes like memory and cpu can be changed online and of course first take effect on reboot, I don't know if the same goes for the cpufeature masking, but it is very likely. So if capable you can write a script that sets all vms cpufeature masking correctly and then it's just planning a restart. I've a powershell script that I use to verify which vms I've set the before mentioned masks on. I only have about 100 vm's, and it took an eternity.

$vms = Get-VM | Sort-Object Name
foreach ($vm in $vms)
{
$views = Get-View $vm.id

foreach ($view in $views)
{
$masks = $view.config.cpuFeatureMask | where-object {$_.Vendor -eq "amd"}
if ($masks.count -ne 5)
{
Write-Host "Error: unexpected number of cpufeature masks, expected 5 got " $masks.count
}
elseif ($masks[1].eax -eq "-----------0--------------------" -and $masks[1].ecx -eq "--------0---------0---------0---" -and $masks[3].ecx -eq "---------------------00000000--0" -and $masks[3].edx -eq "----0------0--------------------")
{
#Write-Host $vm.Name "CPU masking set"
}
else
{
Write-Host $vm.Name "CPU masking NOT set"
}
}
}