Additional steps you must use to restore a DHCP database on a server cluster (816913)


The information in this article applies to:

  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Datacenter Server

SYMPTOMS

When you try to restore a DHCP database that is on a stand-alone clustered server, you cannot stop the DHCP Server service by using the net stop dhcpserver command.

CAUSE

This behavior occurs because the Cluster service controls the DHCP service. Therefore, you cannot use commands such as net stop dhcpserver to stop the DHCP service directly. When you use Cluster Administrator to bring resources online, you must also use it to take those resources offline.

RESOLUTION

To restore a DHCP database to a cluster, you must first take the DHCP service offline to stop the DHCP service in the cluster. To do so, take the DHCP service offline in Cluster Administrator or use the following command:

Cluster . res"dhcp_resource_name" /offline

NoteFor more information about the cluster resource commands, see the "Topic Cluster Resource: Command-line" topic in Microsoft Server 2003 Help and Support Center.

After you take the DHCP resource offline in the cluster, you can restore the DHCP database. For more information about how to do so, click the following article number to view the article in the Microsoft Knowledge Base:

130642 How to move a DHCP database from one server to another in Windows NT 4.0 and in Windows 2000

You must restore the DHCP database on the node that currently owns the DHCP resource. To determine whether the node currently owns the DHCP resource, use Cluster Administrator or the following cluster resource command line:

Cluster resource dhcp_resource_name



Note Do not use the net start dhcpserver command to start the DHCP service as documented in the Knowledge base article 130642. Before you bring the DHCP resource back online, you must make sure that the Cluster service will replicate the newly restored version of the scope configuration. To do this, you must delete the .cpt checkpoint files associated with the DHCP resource. The checkpoint files are on the quorum drive in the quorum_disk\MSCS\dhcp_resource_GUID folder.

To find the GUID in the registry for Windows 2000 Server and Windows Server 2003, locate the following key in the registry:

HKEY_LOCAL_MACHINE\Cluster\Resources

Under this key there is a series of keys that list all the GUIDs. Click each key until you find the correct GUID for the appropriate resource you are looking for. The value for each GUID key named Description determines the correct GUID.

MORE INFORMATION

For more information about restoring or migrating a DHCP database on a stand-alone server, click the following article number to view the article in the Microsoft Knowledge Base:

325473 How to move a DHCP database from a computer that is running Windows NT Server 4.0, Windows 2000, or Windows Server 2003 to a computer that is running Windows Server 2003

The DHCP service uses the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DhcpServer\Configuration

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dhcpserver\Parameters

These keys contain the configuration information for the DHCP service, including the set of scopes that the DHCP service manages. In a cluster configuration, these registry keys are key consistent around the cluster by checkpointing the contents of these keys to a checkpoint file that is stored on the quorum disk.

Before the Cluster service brings the DHCP resource online, the Cluster service uses the contents of the checkpoint file to overwrite the keys on the node with the copy from the checkpoint file. Therefore, if the Cluster service brings the DHCP resource online after a DHCP database and registry key set is restored, the Cluster service overwrites the registry keys with the old data stored in the checkpoint file.

To stop this from occurring and to make sure that the Cluster service uses the restored configuration information, the checkpoint information that the Cluster service holds must be deleted and the newly restored configuration data used to create a new checkpoint file.

You must perform the restore on the node that currently owns the DHCP resource because that is the node where the Cluster service brings the resource online (and the Cluster service uses the registry on that node to re-create the registry checkpoint files).

REFERENCES

Modification Type:MinorLast Reviewed:2/9/2006
Keywords:kbprb KB816913
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