Limitations of Server Clusters

Microsoft has published the following important limitations of Windows Server 2003 clusters:

• Remote storage   These should not be installed on a shared SCSI bus used by the cluster, and you should not configure remote storage devices as cluster resources.

• Disk configuration   External disks cannot be configured as dynamic disks or spanned volumes (volume sets) if they are to be used as cluster resources. The disks to be used for cluster storage must be configured as basic disks and must be formatted using the NTFS file system. They can be configured in hardware RAID configurations in a shared cluster array cabinet or storage unit. Windows Server 2003 does not support the use of dynamic disks or the features of dynamic disks, such as spanned volumes (volume sets), for cluster storage. You also cannot change an existing cluster disk, such as the quorum disk, to a dynamic disk.

• File System   The Encrypting File System, Remote Storage, mounted volumes, or parse points are not supported on cluster storage configurations.

• RAID    You cannot enable a write cache on an internal SCSI RAID controller, nor would you want to for a database application, because the data in the cache will be lost during fail-over. An example of an internal controller is a Peripheral Component Interconnect (PCI) card inside the node. You should enable a write cache on an external RAID controller. An external RAID controller is usually inside the disk cabinet, and the data in the cache will fail over. You cannot use software RAID. You can use hardware RAID to protect the data on your cluster disk as mentioned earlier.

• Network configuration   The Cluster Service only supports TCP/IP, and a single IP address is configured in it. All network interfaces used on all nodes in a server cluster must be on the same network. The cluster nodes must have at least one subnet in common.

• Terminal Services   You can use Terminal Services for remote administration on a server cluster node, but you cannot use Terminal Services for an application server on a server cluster node. If you require load balancing or high availability in a Terminal Service/Application Server environment you will have to acquire separate technology from Citrix Systems, Inc., the Microsoft Terminal Service partner.