Windows Server 2003 Clustering Highlights

Here are some of the highlights of the Cluster Service in Windows Server 2003.

• Windows Server 2003 Enterprise Edition supports 8-node clusters (compared to 2 in Win2K) and Datacenter Edition also supports 8-node clusters (compared to 4 in Win2K).
   
• Server clusters (i.e. clusters based on Microsoft Cluster Service-MSCS) in Windows Server 2003 do not support GUID Partition Table (GPT) disks, a new disk architecture in Windows Server 2003 that supports up to 18 Exabyte disks.
   

• Although Terminal Server can run in application mode on nodes in a Server cluster, there is no failover of Terminal Server sessions.
   

• Clustering is installed by default but you need to configure a cluster by launching Cluster Administrator, or script the configuration using Cluster.exe.
   

• You no longer need to provide a media CD to install Server clusters.
   

• Installing or uninstalling Custer Service no longer requires a reboot.
   

• Remote creation and configuration of the Server cluster is supported.
   

• The default size of the quorum log has been increased from 64KB to 4096KB to support large numbers of file and printer shares (e.g. 200 printer shares).
   

• You no longer need to select which disk is going to be used as the Quorum Resource because it will be automatically configured on the smallest NTFS disk that is larger then 50MB.
   

• Cluster service is Active Directory-aware but it doesn't modify the schema.
   

• The existing volumes can be expanded online without taking down the applications or services.
   

• The Microsoft Distributed Transaction Coordinator (MSDTC) can now be configured once, and then be replicated to all nodes. No need to run COMCLUST.EXE utility on each node any more.
   

• Instead of writing resource DLLS in C or C++ you can now make your existing applications Server cluster-aware by using scripting (VBScript and Jscript).
   

• Unlike Windows 2000, if clustering service loses network connectivity, the TCP/IP stack doesn't get unloaded by default. You don't need to set the DisableDHCPMediaSense registry key any more.
   

• Volume mount points are now supported on shared disks (exclusing the quorom). Volume mount points (Windows 2000 or later) are directories that point to specified disk volumes in a persistent manner (e.g. you can configure C:\Data to point to a disk volume). They bypass the need to associate each disk volume with a drive letter, thereby surpassing the 26 drive letter limitation (e.g. without volume mount points, you would have to create a G: drive to map the “Data” volume to).
   

• Client Side Caching (CSC) is now supported for clustered file shares.
   

• Granular failover control is available for each DFS root. In addition, you can now have multiple stand-alone roots running actively on multiple nodes.
   

• EFS is supported on clustered file shares.
   

• Applications are failed over to spare nodes before active nodes.
   

• Passwords can be reset on multiple clusters at the same time.
   

• Unlike NT/2000, now you can change the Cluster Service account password on the domain as well as on each local node, without having to take the cluster offline.
   

• Resources can be deleted in Cluster Administrator or with Cluster.exe without taking them offline first.
   

• A new tool called ClusDiag is available in the Windows Server 2003 Resource Kit.

Copyright ©2005 Zubair Alexander. All rights reserved.