Installation guide

4 If your environment has vCenter Guided Consolidation, complete the consolidation plan and then
upgrade it to the latest version.
5 Use vSphere Host Update Utility to upgrade ESX 3.x/ESXi 3.5 hosts to ESX 4.0.
This procedure involves putting the host into maintenance mode before you upgrade the host. The
downtime for the procedure depends on the network speed and the server boot time.
In case of upgrade failure, the process supports rollback to the previous release.
For a detailed description of the procedure, see Chapter 11, “Upgrade to ESX 4.0 or ESXi 4.0,” on
page 73.
6 Use the vSphere Client to upgrade your virtual machines:
a If they are not already powered on, power on the virtual machines and upgrade to the latest version
of VMware Tools. This upgrade allows you to use the new features of ESX 4.0.
b Power off the virtual machines and upgrade to the latest version of virtual hardware to take advantage
of the new virtual hardware.
The virtual machine upgrade process has changed in this release. In earlier releases, the virtual hardware
upgrade came before the VMware Tools upgrade. For this release, you must upgrade the VMware Tools
before you upgrade the virtual hardware.
7 Upgrade your product licenses:
a Either your new license keys are sent to you in email, or you get them using the license portal.
b Apply the new license keys to your assets using the vSphere Client (or vCenter Server if you have it).
You must perform these tasks for each ESX/ESXi host and the virtual machines on the hosts.
Upgrading by Moving Virtual Machines Using VMotion
This scenario is known as a migration upgrade. The migration upgrade is a managed transition rather than a
strict upgrade. By using VMotion to move virtual machines directly from one production host to another
production host, you minimize downtime of the virtual machines.
The following example provides a high-level overview of the upgrade process in an environment with
ESX 3.x/ESXi 3.5 and VirtualCenter 2.x, using VMotion to migrate your running virtual machines to
ESX 4.0/ESXi 4.0. The hosts in your environment must be licensed for and able to use VMotion.
You can perform a migration upgrade without VMotion. The only difference is the amount of downtime for
the virtual machines.
The disadvantage of a migration upgrade is that this plan requires additional resources. A migration upgrade
calls for sufficient resources to run the production environment partly on older hosts and partly on upgraded
hosts. Any required redundancies and safeguards must be available on both upgraded and non-upgraded
infrastructure during the transition.
Prerequisites
The requirements for a migration upgrade with VMotion are as follows:
n
One or more machines meeting ESX 4.0/ESXi 4.0 requirements.
n
Empty host storage sufficient to hold a portion of your production virtual machines. Ideally, the storage
should be large enough to hold all of the migrated virtual machines. A larger capacity for virtual machines
on this extra storage means fewer operations are required before all your virtual machines are migrated.
vSphere Upgrade Guide
18 VMware, Inc.