Hi all,
With the help of a few blog posts, I've upgraded our vCenter Server installation from 4.1 to 5.1. Nothing too fancy, everything all on a single VM, managing less than 100 VMs across three hosts.
Everything went well until the time came to update the agents on each host. During the vCenter installation I chose to update them manually. With each attempt to reconnect a host to vCenter, the Tasks pane would show it installing the agent, begin retrieving data from the host, and then promptly fail at the step "Retrieving data from vCenter agent" with the error message "Cannot contact the specified host (host.domain.com). The host may not be available on the network, a network configuration problem may exist, or the management services on this host may not be responding." Of the four hosts I tried to connect, one is running 4.1.0u1 348481 and three are running ESXi 4.1.0u3 800380, one of which has no VMs and is a completely fresh install of ESXi 4.1.0u3, with no previous agent installed. If ESXi 5.1 is installed on that host instead, it's added to vCenter without issue.
Here's what I've looked at so far:
- used netcat to verify that all hosts can be contacted on port 902
- used netstat on vCenter to show it's listening on UDP 902
- disabled the firewall on vCenter
- turning off all but one network port on each host
- restarting / reinstalling the agents on each host
- setting the vCenter Managed IP address and Server Name
- nothing I've found in the logs on the host or vCenter to give any clues to what's failing
Has anyone run into this kind of issue?