VMware KB: Upgrading to vCenter Server 5.0 best practices

VMware supports in-place upgrades on 64-bit systems from vCenter Server 4.x to vCenter Server 5.0. You can upgrade VirtualCenter 2.5 Update 6 or later and vCenter Server 4.0.x to vCenter Server 5.0 by installing vCenter Server 5.0 on a new machine and migrating the existing database.

This upgrade method makes it possible to upgrade from a 32-bit system to a 64-bit system. Alternatively, if the VirtualCenter or vCenter Server database is on a remote machine, you can upgrade the database. vCenter Server 5.0 can manage ESX 3.5.x/ESXi 3.5.x hosts in the same cluster with ESX 4.x/ESXi 4.x hosts.

You cannot upgrade a vCenter Server 4.x instance that is running on Windows XP Professional x64 Edition to vCenter Server 5.0, because vCenter Server 5.0 does not support Windows XP Professional x64. This article provides information about upgrading to vCenter Server 5.0.

VMware KB: Upgrading to vCenter Server 5.0 best practices