How Rolling Upgrades Work (Server Clusters: Rolling Upgrades. Upgrading to Windows Server 2003)

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

In a common scenario, each node runs Windows 2000 Advance Server, with the following software installed:

• Microsoft Server Cluster.

• File Server -- group 3 and 4

• SQL Database -- group 1 and 2

At this point, the cluster is configured as in Figure 1 below so that each node handles client requests.

Figure 1: Configuration where both nodes handle clients

Node 1 is paused, as Figure 2 below shows. All resource groups on Node 1 are moved to Node 2. Because Node 1 is paused, no new groups can be created or moved to this node by users. At this point, Node 2 handles all cluster resource groups. Node 1 is idle and can be upgraded.

Figure 2: Node 1 idle/Node 2 active

At this point, you can start the installation of a service pack or an upgrade to Windows Server 2003 Enterprise Edition (see Figure 3 below). Once the upgrade of Node 1 is complete, you can perform a test to verify that the operating system is fully functional.

Figure 3: Node 1 upgrade

Cluster service maintains each nodes version of the operating system and the Cluster service itself, as well as the aggregate version of the cluster. It uses these version numbers to determine if a node that runs a different operating system version can join a cluster.

Up-level Node 1 rejoins the cluster. Cluster service guarantees that the up-level node understands the down-level nodes protocols and can join a down-level cluster.

Before upgrading Node 2, confirm that the cluster operates correctly. A simple test is to:

1. Select a resource group that is not critical, and move it to Node 1. If this step succeeds, it proves that Cluster service is working.

2. Move this resource group back to Node 2. This step proves that Node 1 did not tamper with the resources in this resource group, and that they will be able to fail back in case Node 1 fails.

Node 2 is paused, as we see in Figure 4 below. All resource groups on Node 2 are moved to Node 1. Because Node 2 is paused, no new groups can be created or moved to this node by other users. At this point Node 1 handles all cluster resource groups. Node 2 is idle and can be upgraded.

Figure 4: Node 1 upgraded/Node 2 idle

You can now start the installation of a service pack or an upgrade to Windows Server 2003 Enterprise Edition on Node 2 (Figure 5 below). Once the upgrade of Node 2 is complete, you can perform a test to verify that the operating system is fully functional. At this point, the up-level Node 2 should successfully join the up-level Node 1.

Figure 5: Node 2 upgraded

Node 2 rejoins the cluster, and you redistribute the resource groups back to both nodes of the cluster configuration, as represented in Figure 6 below.

Figure 6: Windows Server 2003 upgraded Configuration where both nodes handle clients