Yesterday a colleague asked me to add four blades from our old test environment to our new VMware vSphere 4.1 test environment. Of course this was no problem (yet), I had an hour or two to spare, so I started immediately.

Download the ESXi 4.1 installable ISO, connecting this to the four blades, installing and preconfiguring ESXi and adding them to them VMware HA/DRS test cluster. Adjust the zoning for the SAN and configure the correct VLANs and where done. WRONG!

The two running ESX hosts are equipped with Intel Xenon X5660 CPUs, the four extra ESX hosts have Intel Xenon X5430 CPUs. When I tried to do a vMotion the following error message appeared.

Surprise, the CPUs are not compatible. So I needed to setup EVC in this cluster to mask the advanced features from the Intel Xenon X5660 and bring it to the same feature level as the Intel Xenon 5430′s.

But this creates the first ‘chicken or egg dilemma’ of the day.

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