While visiting a customer today, I learned about a technical gotcha that he recently ran across that I thought was worth sharing (especially since it doesn’t appear to be documented yet).  While building out and testing his VI3 Environment, he came across a strange behavior where Update Manager wasn’t working as expected.  He is running his environment on a closed lab there is no DNS and most of the ESX hosts were configured with IP addresses.  Update Manager somehow was configured with a name as well.  When Update Manager sent out requests to the ESX Hosts to fetch a file, it was placing the name in the URL not the IP Address.

My client indicated that the Update Manager documentation didn’t indidcate it requred host name resolution (unconfirmed), but they were eventually able to figure this out from the log files. By adding an entry in the hosts file, teh problem was quickly resolved.

So keep in mind that for Update Manager you want to make sure that you either have DNS capability with all your systems setup in DNS, or have a common hosts file that is shared across all your hosts.