Introduction (Server Clusters: Rolling Upgrades. Upgrading to Windows Server 2003)
Updated: January 1, 2003
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
One of the features of Microsoft Windows Server 2003 Enterprise Edition and Datacenter Edition operating system is the ability to perform a rolling upgrade of the operating system on a server cluster. A rolling upgrade is a process of upgrading cluster nodes, one node at a time, in such a way that services and resources offered by the cluster are always available through out the upgrade process. The system downtime associated with the upgrade is reduced to a few minutesthe time needed to move resources from one node to anotheras compared to the few hours that are usually needed to upgrade a Windows based server.
An administrators can perform rolling upgrade from Windows 2000 Advance Server to Windows Server 2003 Enterprise Edition or from Windows 2000 Datacenter Sever to Windows Server 2003 Datacenter Edition. Rolling upgrade from Windows NT version 4.0 Enterprise edition directly to Windows Server 2003 Enterprise Edition is not supported. This means if you want to upgrade from Windows NT version 4.0 to Server 2003 than you have two options:
You can maintain cluster availability by performing an rolling upgrade to Windows 2000 Advanced Server first, then to Windows Server 2003 Enterprise Edition.
You can perform a non-rolling upgrade directly from Windows NT 4.0 to Windows Server 2003 Enterprise Edition, which will not allow you to maintain cluster availability.
A mixed-version cluster, a cluster composed of nodes running different versions of the operating system, offers the same level of availability as a homogeneous cluster. Resources that support rolling upgrades can be moved, as well as fail over and fail back, between nodes in a mixed mode cluster.
The same procedure can be used to do a rolling upgrade of system hardware or applications if they support it. However, this paper focuses only on the rolling upgrade of the operating system. If you are interested in doing a rolling upgrade of an application, check application documentation to see if the application supports rolling upgrade.
This paper assumes that the reader has a basic knowledge of clustering and is familiar with Microsoft Server Cluster in Windows 2000 operating system and in Windows Server 2003. For more information about these components, consult the Windows Server 2003 Advanced Server Online Help.
The node running an older version of the operation system, application or hardware is called a down-level node.
The node running a newer version of the operation system, application or hardware is called an up-level node.
The cluster composed of nodes running different revisions of the operating system, application, or hardware, is called a mixed-version cluster.