Windows 2000 includes several significant storage technology enhancements, a few of which—Microsoft Dfs, disk quotas, and Encrypting File System (EFS)—I have written about recently. Let's look at some of the enhancements that we haven't covered, including dynamic disks, fault-tolerant disk configurations, and file system changes.

Win2K's Disk Storage
Win2K features basic disk and dynamic disk storage. Basic disk storage, which is much like Windows NT 4.0's storage model, consists of hard disks divided into partitions, with a maximum of four partitions per physical disk. To get around this partition limitation, you can set up one of the partitions as an extended partition, which you can further subdivide into logical drives. Win2K automatically initializes disks as basic disks, so as long as you use a compatible file system, you can access Win2K hard disks locally from NT 4.0, Windows 9x, and DOS.

Dynamic disks are new with Win2K, and you divide them into volumes instead of partitions. You can divide dynamic disks into an unlimited number of volumes per physical disk, and you can perform most disk and volume management tasks without rebooting. A dynamic disk stores its configuration information in a hard disk's final megabyte. Because this organization is different from the traditional disk organizational scheme for Microsoft OSs, you can't access dynamic disks locally from NT 4.0, Win9x, or DOS. If you plan to dual boot Win2K and another OS, don't convert your basic disk to dynamic storage.

Fault-Tolerant Disk Configurations
NT Server 4.0 supports RAID 1 (mirroring) and RAID 5 (stripe sets with parity). Win2K also supports RAID 1 and RAID 5, but you can only create new RAID configurations if you use dynamic storage. Existing RAID 1 and RAID 5 sets on a server that you upgrade from NT 4.0 to Win2K will continue to function and you can continue to manage them, but you can only create new RAID volumes if you have converted your hard disks to dynamic disks. Likewise, you can only extend a volume across one or more drives if you have converted your hard disks.

File System Changes
Partitions or volumes on basic or dynamic disks can use any of the file systems that Win2K supports—NTFS 5.0, FAT32, or FAT16. FAT32, an enhancement to the FAT16 file system, supports larger volume sizes. NT 4.0 doesn't support FAT32, but Windows 9x does; therefore, its inclusion is critical for upgrades to W2K Professional. Also, Win2K's NTFS is an improvement over NT 4.0's because it supports disk quotas and encryption, among other features. To dual boot between Win2K and NT 4.0, you need NT Service Pack 4.0 (Sp4) or later to access any NTFS 5.0 partitions from NT.