I will be install ESXi 5.1 in our lab butt using the free hypervisor version. We already OEM CD's we use from IBM. Could I use one of these CD's on a IBM server in our lab then apply the hypervisor license? From my understanding the binaries are the same it is the license key when opens up the features or not.

Yes, the FREE License Key should work, however, sometimes I have seen some OEM versions require a FREE key from the vendor! Remember also you DO NOT need to apply a key for the first 69 days, it runs in FULL EVALUATION Mode.

Also will the hypervisor 6 key work on 5.1? I need to get 4 separate keys to cover our four test servers but can only register on email account at at time

6.0 keys are different to 5.x keys.

So my question is with a IBM server should I use the OEM CD or download the one generic one from Vmware? What should I do for the hypervisor  license I need to install 5.1 update 3 so it matches our production encviroment

If you are installing on HP, IBM, DELL servers, you should really use the OEM vendors ESXi, if you want to monitor health of server, that's what you are missing. Otherwise just use VMware version without the CIM providers, to communicate with hardware.

Do you need to use the servers long than 60 days, will the evaluation license suffice, otherwise, you will need to register for Free Licenses, and use different email addresses.

The lab environment will need to be up and running well beyond 60-days. This is my concern since you can only download ESXi 6 for the free hypervisor. I am also concerned that the OEM CD will not work with the hypervisor license key..  I would take to go all the work then find out the hardware... :-(

BTW, have you been on vacation you seen to have been quieter than usual lately... LOL :-)

As a licensed VMware users, you should be able to download, any version you like.

However, now that VMware is promoting ESXi 6.0 as the free version, you can only obtain free license keys for 6.0 at present.

It does not take long to install ESXi, 7 minutes, and connect and apply a key.

No vacation here, very few VMware or Virtualisation questions!!

I will have to connect to the vmware site later to see if I can download ESXi 5.1 hypervisor...

BTW,  I have to open questions if you are board and looking for something to do... LOL

lots to do, just come back onto the grid!

I was off the grid for 24 hours!

Even the grand master needs a break now and then.... LOL good for you

I checked the vmware site and as you mentioend before only 6.0 is availbe for download for the hypervisor. Now in vcenter I do see one license key lised for vsphere 5 hypervisor. How can I tell it this if for 5.0 or 5.1.

It looks like I have not choice but to use the OEM CD and hope it will take the license key. My only concern is that I have one license key and not sure if I would break vmware's compliance by using the key on 4 test servers even though the hypervisor edition is free

Even the grand master needs a break now and then.... LOL good for you

No break, actually important Client Meeting over two days - no communications allowed! I do run a business as well!

All keys are for 5.x (5.0, 5.1 and 5.5 are the same!).

It looks like I have not choice but to use the OEM CD and hope it will take the license key. My only concern is that I have one license key and not sure if I would break vmware's compliance by using the key on 4 test servers even though the hypervisor edition is free

I think you know the answer to this! Do I need to say anything here?

I know the correct answer separate keys now the problem is finding the 4 5.x key from vmware