1. Data Storage Requirements
Every partition’s drive letter on the cluster disks must be the same for both nodes in the cluster.

2. Cluster service is based on the shared nothing model of clustering
Cluster service is based on the shared nothing model of clustering. In a shared nothing model, only one node in the cluster can logically control a disk resource at a time. Having only one node controlling a disk resource at any given time allows the Windows 2000 cluster file system to support the native NTFS file system rather than requiring a dedicated cluster-aware file system.

3. Identical Drive Letters
After you have configured the bus, disks, and partitions, you must assign drive letters to each partition on each clustered disk. Drive letters for cluster disks and partitions must be identical on both nodes. For example, Microsoft SQL Server™ is running on a virtual server that Node A controls with the SQL database on drive W. If the virtual server fails over to Node B, SQL server can access data on Node B’s drive W.
Note: It is usually best to assign drive letters from the end of the alphabet to avoid duplicate drive letters.