Supported paths for upgrading to Windows Server 2008

INTRODUCTION

This article lists the supported paths for upgrading to Windows Server 2008.

More Information

The following table outlines the supported upgrade paths that are available to upgrade to Windows Server 2008 storage keeping units (SKUs).

Notes

Unless otherwise specified, all SKUs that are included in this article are x86 and x64 versions.
No upgrade paths are available for Windows Server Web Edition.

Current operating system	Supported path
Windows Server 2003 R2 Standard Edition Windows Server 2003 Standard Edition that has Service Pack 1 (SP1) installed Windows Server 2003 Standard Edition that has Service Pack 2 (SP2) installed Windows Server 2008 Standard Edition Release Candidate 0 (RC0)	Full installation of Windows Server 2008 Standard Edition Full installation of Windows Server 2008 Enterprise Edition
Windows Server 2003 R2 Enterprise Edition Windows Server 2003 Enterprise Edition that has Service Pack 1 (SP1) installed Windows Server 2003 Enterprise Edition that has Service Pack 2 (SP2) installed Windows Server 2008 Enterprise Edition Release Candidate 0 (RC0)	Full installation of Windows Server 2008 Enterprise Edition
Windows Server 2003 R2 Datacenter Edition Windows Server 2003 Datacenter Edition that has Service Pack 1 (SP1) installed Windows Server 2003 Datacenter Edition that has Service Pack 2 (SP2) installed Windows Server 2008 Datacenter Edition Release Candidate 0 (RC0)	Full installation of Windows Server 2008 Datacenter Edition

Other Considerations for Upgrade Scenarios

This section discusses considerations for upgrading Active Directory domain controllers and server applications.

Upgrading Active Directory Domain Controllers

The upgrade process from Windows Server 2003 to Windows Server 2008 requires free disk space for the new operating system image, for the Setup process, and for any installed server roles.

For the domain controller role, the volume(s) hosting the following resources also have specific free disk space requirements:

Application data (%AppData%)
Program files (%ProgramFiles%)
Users' data (%SystemDrive%\Documents and Settings
Windows directory (%WinDir%)

The free space on the %WinDir% volume must be equal or greater than the current size of the resources that are listed and their subordinate folders when they are located on the %WinDir% volume. By default, dcpromo includes the Active Directory database and log files under %Windir%. In this scenario, their size would be included in the free disk space requirements for the %Windir% folder.

However, if the Active Directory database is hosted outside any of the folders here, the hosting volume(s) must only contain additional free space equal to at least 10% of the current Active Directory database size or 250 MB, whichever is larger.

The free space on the volume that hosts the log files must be at least 50 MB.

When you install Active Directory service in Windows Server 2003, the Active Directory database and log files are installed, by default, under the %WinDir%\NTDS folder. In this scenario, the NTDS.DIT database file and all the log files are temporarily copied to the quarantine location and then copied back to their original location. Therefore, additional free disk space is required for the resources. However, the SYSVOL directory that is also located under the %WinDir% directory is moved and not copied. Therefore, it requires no additional free space.

After the upgrade, the space that was reserved for the copied resources will be returned to the file system.

Upgrading Server applications

Because of fundamental changes that are implemented in Windows Server 2008, some server applications may require pre-upgrade and post-upgrade preparation. In some cases, the server applications must be removed before upgrading from Windows Server 2003 to Windows Server 2008 and reinstalled after the upgrade.

Exchange Server

You cannot install Exchange Server 2007 on Windows Server 2008. You can install Exchange Server 2007 Service Pack 1 (SP1) on Windows Server 2008.

When you upgrade stand-alone servers, you cannot upgrade your operating system to Windows Server 2008 and then upgrade Exchange Server 2007 to Exchange Server 2007 SP1. You also cannot upgrade Exchange Server 2007 to Exchange Server 2007 SP1 and then upgrade your operating system to Windows Server 2008.

To deploy Exchange 2007 SP1 on Windows Server 2008, you must install Windows Server 2008 on a computer that does not have Exchange Server 2007 installed, and then install Exchange 2007 SP1.

SQL Server

No pre-upgrade or post-upgrade preparation is required to upgrade Windows Server 2003-based computers that are running Microsoft SQL Server.

SharePoint Server

You can upgrade a Windows Server 2003-based computer that is running Microsoft Windows SharePoint Services to Windows Server 2008. Typically, Windows Server 2003-based computer that is running SharePoint Server 2007 to Windows Server 2008 is a supported upgrade scenario.

Office Communications Server

Currently, upgrade of Windows Server 2003-basedcomputers that are running Office Communications Server 2007 to Windows Server 2008 is not supported. Later versions of Windows Server 2008 may support such upgrades.

Failover Clustering

Currently, upgrade of Windows Server 2003-based computers that are configured for failover clustering to Windows Server 2008 is not supported.

Other Applications

Application teams are currently testing their products to determine supportability for upgrade scenarios. This information will be provided when the information becomes available.

References

For more information about how to resolve issues regarding Exchange Server 2007 services after you upgrade to Windows Server 2008, click the following article number to view the article in the Microsoft Knowledge Base:

951402 Multiple Exchange Server 2007 services do not start when you upgrade a computer that is also running Windows Server 2003 to Windows Server 2008

For more information about SQL Server 2005 issues when you upgrade Windows Server 2003 Service Pack 2 to Windows Server 2008, click the following article number to view the article in the Microsoft Knowledge Base:

948594 Problems occur on a server that is running SQL Server 2005 when you upgrade Windows Server 2003 Service Pack 2 to Windows Server 2008

For more information about Microsoft server applications that are supported on Windows Server 2008, click the following article number to view the article in the Microsoft Knowledge Base:

948680 Description of the Microsoft server applications that are supported on Windows Server 2008

For more information about upgrading the operating system of a clusterd server to Windows Server 2008, click the following article number to view the article in the Microsoft Knowledge Base:

935197 You cannot upgrade the operating system of a clustered server from Windows Server 2003 to Windows Server 2008