Understanding the Migration Process from a Cluster Running Windows Server 2003

Applies To: Windows Server 2008

You can use a wizard to migrate the settings of some types of resources from a cluster running Windows Server 2003 to a cluster running Windows Server 2008. This topic describes some limitations for this process and provides an overview of several approaches to using the process. From the third page of the wizard, you can view a premigration report that explains whether each resource is eligible for migration and describes additional steps to perform after running the wizard. After the wizard finishes, it provides a report that describes additional steps for completing the migration.

For information about the specific steps for running the Migrate a Cluster Wizard, see Migrate Clustered Resource Groups from Windows Server 2003.

This topic contains the following subsections:

• Identifying which clustered services or applications can be migrated from a cluster running Windows Server 2003

• Migration scenario A: Both old and new clusters have multiple nodes when you migrate settings

  Follow this scenario if you can create a multiple-node cluster running Windows Server 2008 and then migrate settings to it from a multiple-node cluster running Windows Server 2003.

• Migration scenario B: Both old and new clusters have one node when you migrate settings (in-place migration for a two-node cluster)

  Follow this scenario for an in-place migration of a two-node cluster running Windows Server 2003 to a two-node cluster running Windows Server 2008. With this scenario, you use the same physical servers for a new two-node cluster as you used for the old one (although this scenario is not a rolling upgrade).

  Note that the hardware for the new cluster must meet the requirements for a cluster running Windows Server 2008. For more information, see Understanding Requirements for Failover Clusters.

• Why rolling upgrades are not possible from Windows Server 2003

Identifying which clustered services or applications can be migrated from a cluster running Windows Server 2003

This section lists the clustered services or applications (clustered resources) that can be migrated from a server cluster running Windows Server 2003.

Resources for which the Migrate a Cluster Wizard performs most or all of the migration steps

After you use the Migrate a Cluster Wizard to migrate the settings of the following resources to a failover cluster running Windows Server 2008, few or no additional steps are needed before the resources can be brought online.

• File Share: You can migrate settings for a File Share resource and for the associated Physical Disk, IP Address, and Network Name resources.

  The Migrate a Cluster Wizard automatically translates File Share resources in Windows Server 2003 to the resource types used in Windows Server 2008. Therefore, some resources might look different after the migration. The following table provides details:

  Resource as Seen in Server Cluster Running Windows Server 2003	Migrated Rresource as Seen in Failover Cluster Running Windows Server 2008
  One File Share resource	One File Server resource
  Multiple File Share resources	Multiple File Server resources within a single clustered file server
  File Share resource with DFS root	Distributed File System resource and File Server resource (both within a clustered DFS Server)

• Physical Disk: You can migrate settings for Physical Disk resources other than the quorum resource.

  You do not need to migrate the quorum resource. When you run the Create a Cluster Wizard, the cluster software automatically chooses the quorum configuration that will provide the highest availability for your new failover cluster. You can change the quorum configuration settings if necessary for your specific environment. For information about changing settings (including quorum configuration settings) for a failover cluster, see Modifying Settings for a Failover Cluster.

• IP Address: You can migrate IP Address settings other than the cluster IP address. IP addresses are eligible for migration only within the same subnet.

• Network Name: You can migrate Network Name settings other than the cluster name. If Kerberos authentication is enabled for the Network Name resource, the wizard will prompt you for the password for the Cluster service account that is used by the old cluster.

Resources for which the Migrate a Cluster Wizard does not perform all of the migration steps

After you use the Migrate a Cluster Wizard to migrate the settings of the following resources to a failover cluster running Windows Server 2008, some additional steps are needed before the resources can be brought online:

• DHCP Service

• WINS Service

• Generic Application

• Generic Script

• Generic Service

The wizard provides a report that describes the additional steps that are needed. Generally, the steps you must take include:

• Installing server roles or features that are needed in the new cluster (all nodes). When migrating DHCP, you must install the DHCP Server role, and when migrating WINS, you must install the WINS feature.

• Copying or installing any associated applications, services, or scripts on the new cluster (all nodes).

• Ensuring that any data is copied.

The resource settings are migrated, as are the settings for the IP Address and Network Name resources that are in the resource group. If there is a Physical Disk resource in the resource group, the settings for the Physical Disk resource are also migrated.

Migration scenario A: Both old and new clusters have multiple nodes when you migrate settings

For this migration scenario, there are three phases:

1. Install two or more new servers, run validation, and create a new cluster. For this phase, while the old cluster continues to run, install Windows Server 2008 and Failover Clustering on at least two servers. Create the networks the servers will use, and connect the storage. Next, run the complete set of cluster validation tests to confirm that the hardware and hardware settings can support a failover cluster. Finally, create the new cluster. At this point, you have two clusters.

   Additional information about connecting the storage: If the new cluster is connected to old storage, make at least two logical unit numbers (LUNs) or disks accessible to the servers, and do not make those LUNs or disks accessible to any other servers. (These LUNs or disks are necessary for validation and for the witness disk, which is similar to, although not the same as, the quorum resource in Windows Server 2003.) If the new cluster is connected to new storage, make as many disks or LUNs accessible to it as you think it will need.

   The steps for creating a cluster are listed in Checklist: Create a Failover Cluster.

2. Migrate settings to the new cluster and determine how you will make any existing data available to the new cluster. When the Migrate a Cluster Wizard completes, all migrated resources will be offline. Leave them offline at this stage. If the new cluster will use old storage, plan how you will make the storage available to it, but leave the old cluster connected to the storage until you are ready to make the transition. If the new cluster will use new storage, copy the appropriate folders and data to the storage.

3. Make the transition from the old cluster to the new. If the new cluster uses old storage, the first step in the transition is to follow your plan for making LUNs or disks inaccessible to the old cluster and accessible to the new cluster. Then, whether the new cluster uses new or old storage, take each resource group offline on the old cluster and bring the corresponding clustered service or application online on the new cluster.

Migration scenario B: Both old and new clusters have one node when you migrate settings (in-place migration for a two-node cluster)

For this migration scenario, there are three phases:

1. Install a new server and run selected validation tests. For this phase, allow one existing server to keep running Windows Server 2003 and the Cluster service while you begin the migration process. On one other server, install Windows Server 2008 and the failover cluster feature. Connect this server to storage, make at least one LUN or disk accessible to it (a LUN or disk that is not accessible to other servers), and run all tests that the Validate a Configuration Wizard will run. The wizard will recognize that this is a single node and limit the tests that it runs. Tests that require two nodes (for example, tests that compare the nodes or that simulate failover) will not run.

   Note that the tests that you run at this stage do not provide complete information about whether the storage will work in a cluster running Windows Server 2008. As described later in this section, you will run the Validate a Configuration Wizard later with all tests included.

2. Make the new server into a single-node cluster and migrate settings to it, and determine how you will make existing data available to the new cluster. Migrate settings to the single-node cluster, but keep clustered resources offline. If the new cluster will use the old storage, leave the data on the old storage, and create a plan for making the disks or LUNs accessible to the new cluster. If the new cluster will use new storage, copy folders and data to appropriate LUNs or disks in the new storage, and make sure those LUNs or disks are visible to the new server (and not visible to any other servers).

3. Make the transition from the old cluster to the new. This phase might involve some downtime. Install Windows Server 2008 and the failover cluster feature on the server that was previously in the old cluster and connect the networks and storage so the new server can join the new cluster.

   If the appropriate disks or LUNs are not already accessible to the new cluster, make them accessible, and run the complete set of validation tests on the new cluster. Confirm that the settings for the migrated services or applications are correct. Finally, on the new cluster, bring the migrated services and applications online.

Why rolling upgrades are not possible from Windows Server 2003

When you shift your clustering operation from servers running Windows Server 2003 to servers running Windows Server 2008, you cannot perform a rolling upgrade, that is, you cannot have nodes running different operating systems in the same cluster. Improvements in failover clusters in Windows Server 2008 mean that the two versions of clustering—server clusters in Windows Server 2003 and failover clusters in Windows Server 2008—use very different underlying functionality for communication with storage and for networking. Storage in failover clusters uses specific SCSI commands (within the standard called SCSI Primary Commands-3 or SPC-3) not used in Windows Server 2003. Networking improvements mean that clustered servers running Windows Server 2008 perform node-to-node communication differently from clustered servers running Windows Server 2003.

Additional references

• Migrating Settings from a Server Cluster Running Windows Server 2003

• For information about hardware compatibility for Windows Server 2008, see https://go.microsoft.com/fwlink/?LinkID=59821.

• For design and deployment information (including migration information) for failover clusters, see https://go.microsoft.com/fwlink/?LinkId=86168.