Storage Features in Windows Server 2003 and Clustering

Applies To: Windows Server 2000, Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Volume Mount Points

Server clustering in Windows Server 2003 supports volume mount points, which are directories on a volume that an application can use to "mount" a different volume, that is, to set it up for use at the location a user specifies. This feature is not supported in Windows NT 4.0 or Windows 2000.

EFS

With Windows Server 2003, the encrypting file system (EFS) is supported on clustered file shares. To enable EFS on a clustered file share, you must perform a number of tasks to configure the environment correctly:

EFS can only be enabled on file shares when the virtual server has Kerberos enabled. By default, Kerberos is not enabled on a virtual server. To enable Kerberos you must check the Enable Kerberos Authentication check box on the network name resource that will be used to connect to the clustered file share.

All cluster node computer accounts, as well as the virtual server computer account, must be trusted for delegation. See online help for how to do this.

To ensure that the users private keys are available to all nodes in the cluster, you must enable roaming profiles for users who want to store data using EFS. See online help for how to enable roaming profiles.

Once the cluster file shares have been created and the configuration steps above have been carried out, users data can be stored in encrypted files for added security.

Disk Quotas

Configuring disk quotas on shared disks is supported in Windows 2000 and Windows Server 2003.

Autochk/Chkdsk/Chkntfs - Every time Windows restarts, Autochk.exe is called by the Kernel to scan all volumes to check if the volume dirty bit is set. If the dirty bit is set, autochk performs an immediate chkdsk /f on that volume.

Chkdsk is a native Windows tool that can determine the extent of file and file system corruption. If Chkdsk runs in write-mode, it will automatically attempt to remedy disk corruption.

The Chkntfs.exe utility is available in Microsoft Windows NT 4.0 Service Pack 2 and later versions of Windows. It is designed to disable the automatic running of chkdsk on specific volumes, when Windows restarts from an improper shutdown. Chkntfs can also be used to unschedule a chkdsk if chkdsk /f was used to schedule a chkdsk on an active volume on the next system restart.

All of the above are supported to run in specific configurations in Server Clusters. The relevant KB articles that explain the procedures in detail are:

174617 - Chkdsk runs while running Microsoft Cluster Server Setup

176970 - How to Run the CHKDSK /F Command on a Shared Cluster Disk

160963 - CHKNTFS.EXE: What You Can Use It For

Virtual Disk Service - The Virtual Disk Service will ship in Server 2003. It provides an interface for software volume management, hardware RAID cabinet management, multi-path and device allocation in a SAN. VDS will be supported in Server Clusters. Additional providers (supplied by ISVs like Veritas) are required to enable cluster functionality.

Virtual Snap Shot and TimeWarp - VSS is a Windows service that allows users to snapshot data. It does this with the help of hardware or software providers that actually implement the functionality. VSS coordinates requestors, providers, and writers. The Volume Shadow Copy service is abbreviated as VSS. Software providers are implemented as a user-mode component plus a kernel-mode driver. I/Os are intercepted by the driver that instantiates snapshot volumes. The driver may be a storage filter driver or a component of a volume manager. A writer is any application that stores persistent information on one or more volumes, and participates in snapshot synchronization. Typically this might be a database (e.g. SQL Server) or system service (e.g. Certificate Services) or a backup program (Backup). VSS implementation in NT backup is fully supported by server clusters. Timewarp is another specific use of snapshots for simple file un-delete and is a feature available in Windows Server 2003. This is also fully supported in clustering and the whole feature set can be enabled on clustered and non clustered disks in the same fashion. End user experience remains unchanged.