The vSphere Upgrade Guide describes how to upgrade from earlier versions of VMware® ESX™, ESXi, and VMware vCenter™ Server to ESX 4.0/ESXi 4.0 and vCenter Server 4.0.

This guide includes the following tasks:

Upgrade to vCenter Server 4.0.

Install vCenter Server 4.0 on a different machine and keep the VirtualCenter 2.x database. You would do this if you are upgrading from a 32-bit server to a 64-bit server, for example.

Upgrade to ESX 4.0 from ESX 3.x.

Upgrade to ESXi 4.0 from ESXi 3.5.

Upgrade to ESX 4.0 from ESX 2.5.x using upgrade VMotion.

Upgrade to ESX 4.0 from ESX 2.5.x using cold migration.

Change ESX to ESXi and the reverse.

Upgrade VMware Tools and virtual hardware.

To learn how to simplify and automate your datacenter upgrade, see the vCenter Update Manager Administration Guide.

If you have legacy versions of ESX, ESXi, and VirtualCenter, and you want to migrate to VMware vSphere™ 4.0 by performing fresh installations that do not preserve existing data, see the following manuals:

ESX and vCenter Server Installation Guide

ESXi Installable and vCenter Server Setup Guide

ESXi Embedded and vCenter Server Setup Guide

This book is intended for anyone who needs to upgrade from earlier versions of ESX/ESXi and vCenter Server to ESX 4.0/ESXi 4.0 and vCenter Server 4.0. The information in this manual is written for experienced Microsoft Windows or Linux system administrators who are familiar with virtual machine technology and datacenter operations.

VMware welcomes your suggestions for improving our documentation. If you have comments, send your feedback to

The vSphere documentation consists of the combined VMware vCenter Server and ESX/ESXi documentation set.

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VMware Professional Services

VMware Education Services courses offer extensive hands-on labs, case study examples, and course materials designed to be used as on-the-job reference tools. Courses are available onsite, in the classroom, and live online. For onsite pilot programs and implementation best practices, VMware Consulting Services provides offerings to help you assess, plan, build, and manage your virtual environment. To access information about education classes, certification programs, and consulting services, go to