We are still running ESX 3.0.x and VC 2.0.x. I thought about upgrading vcenter first and then just upgrading the servers has time permits. But if there’s going to be odd issues like this, even if its only when you install some patches. I think I’ll try to put together a much shorter timeline to move to 3.5
Heads up—I’ve been alerted to a potential problem when using ESX Server 3.0.x with VirtualCenter 2.5. Quoting from this VMware KB article:
ESX Server 3.0.x hosts managed by VirtualCenter 2.5 must have their Host Agent (hostd) specially configured to work with VirtualCenter 2.5. This configuration is done automatically during the initial installation of the VirtualCenter Agent (vpxa). If an ESX Server patch is subsequently applied that includes the esx-hostd RPM package, like ESX Server patch 1002435, the patch replaces the existing Host Agent (hostd) configuration file (/etc/vmware/hostd/config.xml) and undoes vpxa’s changes. This reverting of the Host Agent configuration file breaks connectivity with VirtualCenter 2.5.