Scenario, VMware environment, based on a VMware vCenter 4.0 Update 1 Server and a few ESX 3.5 hosts. It is time to install the latest patches, the preferred approach is the VMware Update Manager. You attach a baseline, Scan for updates and receive a confirmation it is about time. Next step is Stage your hosts and a few moments later you receive this message: “VMware vCenter Update Manager had an unknown failure. Check Tasks and Events tab and logs for more details”.
Just before I was going to deep dive into this, my colleague Ronald pointed me to VMware KB 1026140, subject: Unable to stage updates on ESX 3.5 hosts using VMware Update Manager 4.x. As the subject already suggests, “VMware Update Manager 4.x supports patches and extensions staging only for ESX/ESXi 4.x hosts. You cannot stage patches to ESX 3.5 hosts and PXE booted ESXi hosts.”
So, skip over Staging and go directly to Remediate to install the patches.