So I just completed (or so I thought) the upgrade to ESXi 5.1 from 4.1. All of my hardware is compatible. I did receive a warning during the migration that I had some VIP stuff loaded in 4.1 but what it was loaded for I didn't have. So the upgrade completed and when the host rebooted, I saw the new 5.1 boot screen, then after that completed loading and it went to the half grey/half yellow screen it says 4.1. My Fat client for Winders also reads 4.1. Is it possible that the upgrade didn't complete even though it said it did? I put all of my hosts into suspend mode. The only thing I didn't do now that I'm thinking about it, is put the host into maintenance mode. Will that be a deal breaker and I"ll have to suspend all of my guests again? Thank you all in advance for your help with this.
