Disk Management

The Disk Management snap-in to the Microsoft Management Console (MMC) is a tool for managing disk storage systems. Wizards guide you through creating partitions or volumes and initializing or upgrading disks. New key features of Windows 2000 Server Disk Management include the following:

Online Disk Management    You can perform most administrative tasks without shutting down the system or interrupting users. For example, you can create various partition layouts and choose protection strategies, such as mirroring and striping, without restarting the system. You can also add disks without restarting. Most configuration changes take effect immediately.

Remote Disk Management    As an administrator, you can manage any remote (or local) computer that runs Windows 2000.

Figure 19.2 shows some of the View menu options you can select in Disk Management.

Figure 19.2 Disk Management MMC Snap-In

Basic and Dynamic Storage

There are two types of disk storage available with Windows 2000: basic or dynamic. Basic storage supports partition-oriented disks. A basic disk can hold primary partitions, extended partitions, and logical drives. Basic disks might also contain spanned volumes (volume sets, mirrored volumes (mirror sets, striped volumes (stripe sets, and redundant array of independent disks or RAID-5 volumes. In Microsoft® Windows NT® version 4.0 or earlier, RAID-5 was known as a stripe set with parity. If you want computers to access these volumes, and if those computers run Windows NT 4.0 or earlier, Microsoft® Windows® 98 or earlier, or Microsoft® MS-DOS®, you need to create basic volumes.

Dynamic storage supports new volume-oriented disks and is new with Windows 2000. It overcomes the restrictions of partition-oriented disk organization and facilitates multidisk, fault-tolerant disk systems. With dynamic storage, you can perform disk and volume management without restarting the operating system. On a dynamic disk, storage is divided into volumes instead of partitions. A volume consists of a portion or portions of one or more physical disks in any of the following layouts: simple, spanned, mirrored, striped, and RAID-5 volumes. Dynamic disks cannot contain partitions or logical drives, and cannot be accessed by MS-DOS or Microsoft® Windows® 98 and earlier versions. You can use dynamic storage to set up a fault-tolerant system by using multiple disks.

When you attach a new disk to your computer, you need to initialize the disk before you can create volumes or partitions. When you initialize the disk, select dynamic storage if you want to create simple volumes on the disk or if you plan to share the disk with other disks to create a spanned, striped, mirrored, or RAID-5 volume. Select basic storage if you want to create partitions and logical drives on the disk.

Table 19.2 shows tasks that you can perform on basic and dynamic disks by using Disk Management.

Table   19.2 Tasks for Basic and Dynamic Disks

Volume Management

Windows 2000 includes significant improvements in the architecture of volume management. Volume management includes the processes that create, delete, alter, and maintain storage volumes in a system. The new architecture improves the manageability and recoverability of volumes in an enterprise environment.

A Logical Disk Manager (LDM) has been introduced to the architecture to extend fault tolerance functionality, to improve system recovery, to encapsulate volume information so that disks can be easily moved, and to provide improved management functionality. This service is responsible for volume creation and deletion, fault tolerance features (RAID), and volume tracking. You use the Disk Management snap-in to manage local and remote volumes.

Volume management has the following features:

• You can create any number of volumes in the free space on a physical hard disk or create volumes that span two or more disks.

• Each volume on a disk can have a different file system, such as the file allocation table (FAT) file system or the NTFS file system.

• Most changes that you make to your disk are immediately available. You do not need to quit Disk Management to save them or restart your computer to implement them.

Volume Mount Points

As part of Disk Management, you can create volume mount points. Volume mount points provide you with a quick way to bring data online and offline. They are file system objects in the Windows 2000 internal namespace that represent storage volumes. When you place a volume mount point in an empty NTFS directory, you can graft new volumes into the namespace without requiring additional drive letters. An example of how you might use volume mount points is to have a computer with a single drive and volume formatted as C and to mount a disk as C:\Games.

Some possible uses for volume mount points include:

To provide additional space for programs    For example, you mount a disk as C:\Program Files. Then, when you need additional disk space, you add a disk to the system and span it with the disk at C:\Program Files.

To create different classes of storage    For example, create a stripe set for performance and mount it as C:\Scratch; and create a mirror set for robustness and mount it as C:\Projects. Users will see the directories normally, but their scratch directory will be fast, and their projects directory will be protected by a mirror set.

To create multiple mount points for a volume    For example, a volume is mounted as C:\Games and C:\Projects. Be aware that nothing prevents cycles in the namespace. If you mount a volume as D and also as D:\Docs, because D is mounted underneath itself, it creates a cycle in the namespace. Applications that do enumeration get into an endless loop on this volume.

Volume mount points are robust against system changes that occur when hardware devices are added to or removed from a computer. You are no longer limited to the number of volumes you can create based on the number of drive letters.

Disk Defragmentation

Another Disk Management feature is the Disk Defragmenter. You can use this tool to locate files and folders that have become fragmented and to reorganize clusters on a local disk volume. Disk Defragmenter organizes clusters so that files, directories, and free space are physically more contiguous. As a result, your system can gain access to your files and folders and can save new ones more efficiently. If you have considerable fragmentation, Disk Defragmenter can improve your overall system performance significantly in relation to disk input/output (I/O).

The Disk Defragmentation feature decides where files should be located on the disk, but NTFS and FAT move the clusters around.

You can use this tool with disk volumes that are formatted for FAT16, FAT32, or NTFS.

Considerations for Using Dynamic Storage

Consider the following when creating volumes:

• Dynamic storage uses a volume-oriented scheme for disk organization. Windows NT Server is not compatible with dynamic disks.

• You can use the Windows 2000 Setup program to configure disk space while upgrading to Windows 2000 Server.

Note

You can create new volumes and partitions on unallocated portions of the disk without losing data on existing volumes. However, if you plan to change your volume topology, you have to backup your data because making changes to existing volumes erases all existing data.

• You can configure the internal hard disk on a new computer during initial setup when you load the Windows 2000 Server operating system software. You can use Disk Management to make changes to the disk after installation.

For more information about managing disks, see "Disk Concepts and Troubleshooting" and "Data Storage and Management" in the Microsoft ® Windows ®  2000 Server Resource Kit Server Operations Guide.