I have a set of ESX 3.5 servers in 2 different datacenters. One is DR, one is production. They are on the same vlan and so I can access any of them on the private network from my vCenter server. Last month, as a learning experience (I hadn't dealt with ESX much before), I updated the DR server.

Other than finding out that a couple of bundles had to be installed manually in order to get the rest to install from vCenter, it went off without a hitch.

Now, I'm trying to do the same for our production servers and it is not working. I've googled around for the error I get during scan, and investigate loads of different solutions (editing the integrity file, checking DNS, etc) -- I did install the 2 bundles that had to be installed manually already -- but scan from vCenter is just not working.

Side note: I did just scan the DR server again and that scan works fine so shouldn't be a problem with vCenter that has cropped up recently -- it has to be something else.

The error I get is:

Patch metadata for (servername) missing. Please download updates metadata first.
Failed to scan (servername) for updates.

I'm all out of ideas on how to make this work, so any help would be hugely appreciated.