I currently have an esxi 4.1 host using an enterprise plus evaluation key. It was previously using an esxi 4 enterprise key, but I needed to use more than 4 cores on a virtual machine. I upgraded my enterprise 4 to key to an enterprise 5 key, because I want to upgrade the host to 5.
My question is, to get this upgraded without any issues, will I need to switch back to my enterprise 5 key, then downgrade all my virtual machine back to 4 core, then upgrade the host? Or can I go straight to version 5 on this enterprise plus 4 evaluation key, then switch to my enterprise 5 key?
One question about upgrades - I have heard that during upgrade it's possible to format one of the LUNs, so the recommendation is to remove the san cables from the host. I was wondering whether this risk is still present if I choose to upgrade via the update manager? Just looking for the safest and efficient method.