Just a very quick posting about a problem we were experiencing on the weekend while doing some VMware upgrades and what the solution was.
We were upgrading our virtual centre and esx hosts to version 4, we had upgraded the esx hosts to the latest version of ESX3.5 prior to upgrading the virtual centre sever as this is a prerequisite for the agent to communicate with virtual centre 4. We upgraded the Virtual Centre server without any problems and rebooted the server. We logged back in and started to now try migrate vm’s from one of the esx hosts to another so that we could start the upgrading of the ESX hosts to vSphere. We selected a low priority vm initially to make sure vmotion hadn’t been affected and selected migrate,once we got to the destination selection page, as soon as we selected a host to move the vm to the server thought about it for about twenty seconds and then dropped us out of the vicleint session. We tested from differing boxes to others and it was affecting all VMotioning between the hosts. I checked the task manger services tab of the virtual centre as we tried the VMotioning and each time the vpxd service would double in processing then stop thereby kicking us out of our session and a manual restart had to be done.
After speaking to a colleague Simon Phillips he mentioned something him and I had done for another of our environments where we removed the hosts from the virtual Infrastructure and re-added it so that the agent could reconnect after we had done upgrades. We tried to do this but there was an ESX3.x cluster in place. Luckily it had no configurations so we removed the cluster with the hosts included from the environment(as this is obviously unavoidable unless the hosts are put in maintenance mode) and re-added the hosts one by one without any problems. Once we had done this we tried the migrations again and they worked perfectly. So it was either down to the old 3.5 cluster causing problems now that virtual centre had been upgraded or the re-adding of the hosts to the environment helped upgrade/reconnect the host agents and allow VMotion.
We did scour the web for anyone or any page mentioning this but we never came across it so hopefully this helps someone save some time or a call to VMware.
Thanks to Simon for his reminder of what we did before and for jumping online to help us and Gabe Martinez for sitting with me till 1am completing the upgrade