VMware provides limited support for ESX 3.0.0 and 3.0.1 under certain conditions.

When you upgrade from ESX 3.0.0 and 3.0.1 to ESX 4.0 Update, you can perform a migration upgrade with or without VMotion. In a migration upgrade, you migrate ESX 3.0.0 and 3.0.1 virtual machines to ESX 4.0 Update hosts, as follows: Evacuate the virtual machines from the ESX 3.0.0 or 3.0.1 host. Do a fresh install of ESX 4.0 Update. Migrate the virtual machines back to the newly installed ESX 4.0 Update host. See Upgrading by Moving Virtual Machines Using Upgrade VMotion.

Direct, in-place upgrade from ESX 3.0.0 and 3.0.1 to ESX 4.0 Update is not supported. You can perform a standalone host upgrade by upgrading to a later version of ESX 3.x or 4.0 as an intermediary step.

For information about upgrading ESX 3.0.0 and 3.0.1 to a later version of ESX 3.x, see the VMware Infrastructure 3 documentation.

For upgrading ESX 3.x to ESX 4.0, you can use vSphere Host Update Utility or vCenter Update Manager.