Lesson 1: Introduction to Disk Management

If you have free space on your hard disk, you need to partition and format it so that you can store data on that part of the disk. In addition, if you have more than one hard disk, each disk will also have to be partitioned and formatted so that you can store data on it. Windows 2000 supports two types of disk storage: basic storage and dynamic storage. A physical disk must be either basic or dynamic; you cannot use both storage types on one disk. You can, however, use both types of disk storage in a multidisk system.

Before Windows 2000, the only type of disk storage available was the industry standard that is referred to in Windows 2000 as basic storage. It dictates the division of a hard disk into partitions. A partition is a portion of the disk that functions as a physically separate unit of storage. Windows 2000 recognizes primary and extended partitions. A disk that is initialized for basic storage is called a basic disk. A basic disk can contain primary partitions and extended partitions with logical drives. For Windows 2000, basic storage is the default, so all disks are basic disks until you convert them to dynamic storage. Basic storage in Windows 2000 provides compatibility with disk partitions and sets created with Microsoft Windows NT 4.0.

In Windows 2000, you can create, delete, and format partitions without having to restart your computer to make the changes effective. When you create partitions, you should leave a minimum of 1 megabyte (MB) of unallocated space on the disk in case you decide later to convert the basic disk to a dynamic disk. The conversion process creates a 1 MB region at the end of the dynamic disk in which it stores a database that tracks the configuration of all dynamic disks in the computer.

You can divide a basic disk into primary and extended partitions. This allows you to separate different types of information, such as user data on one partition and applications on another. A basic disk can contain up to four primary partitions, or up to three primary partitions and one extended partition, for a maximum of four partitions, and only one partition can be an extended partition (see Figure 11.1.)

Figure 11.1 Partition types

Windows 2000 can use one of the primary partitions to start the computer. The computer looks for the boot files to start the operating system on the primary partition that has been designated as the active partition. Only a primary partition can be marked as the active partition and only one partition on a single hard disk can be active at a time. To dual boot Windows 2000 with Microsoft Windows 95 or MSDOS, the active partition must be formatted as file allocation table (FAT) because Windows 95 cannot read a partition formatted as FAT32 or NT file system (NTFS).

There can be only one extended partition on a hard disk, so it is important to include all remaining free space in the extended partition. Unlike primary partitions, you do not format extended partitions or assign drive letters to them. You divide extended partitions into segments. Each segment is a logical drive. You assign a drive letter to each logical drive and format it with a file system.

A disk that you convert from basic storage to dynamic storage is a dynamic disk. Only Windows 2000 supports dynamic disks. Dynamic disks contain dynamic volumes, which can consist of a portion, or portions, of one or more physical disks. A dynamic disk can contain simple volumes, spanned volumes, mirrored volumes, striped volumes, and redundant array of independent disks-5 (RAID-5) volumes. These volume types will be discussed shortly.

Dynamic storage has several advantages:

• Volumes can be extended to include noncontiguous space on the available disks.
• There is no limit on the number of volumes you can create per disk.
• Disk configuration information is stored on the disk, rather than in the registry or in other places where it might not be accurately updated. The disk configuration information is also replicated to all other dynamic disks so that one disk failure will not obstruct access to data on other disks.

You can convert basic disks to dynamic storage and then create Windows 2000 volumes. Consider which volume type best suits your needs for efficient use of disk space, performance, and fault tolerance. Fault tolerance is the ability of a computer or operating system to respond to a catastrophic event without loss of data. In Windows 2000, mirrored volumes and RAID-5 volumes are fault tolerant.

A simple volume contains disk space from a single disk and provides no fault tolerance. A simple volume can be mirrored to provide fault tolerance.

A spanned volume includes disk space from two or more disks (up to 32 disks). Windows 2000 writes data to a spanned volume on the first disk, completely filling the space, and continues in this manner through each disk that you include in the spanned volume. A spanned volume provides no fault tolerance. If any disk in a spanned volume fails, the data in the entire volume is lost. Spanned volumes in Windows 2000 are similar to volume sets in Windows NT 4.0.

A mirrored volume consists of two identical copies of a simple volume, each on a separate hard disk. Mirrored volumes provide fault tolerance in the event of hard disk failure. Mirrored volumes in Windows 2000 are similar to mirror sets in Windows NT 4.0.

A striped volume combines areas of free space from multiple hard disks, up to 32, into one logical volume. In a striped volume, Windows 2000 optimizes performance by adding data to all disks at the same rate. If a disk in a striped volume fails, the data in the entire volume is lost. Striped volumes in Windows 2000 are similar to stripe sets in Windows NT 4.0.

A RAID-5 volume is a fault-tolerant striped volume. Windows 2000 adds a parity-information stripe to each disk partition in the volume. Windows 2000 uses the parity-information stripe to reconstruct data when a physical disk fails. A minimum of three hard disks is required in a RAID-5 volume. RAID-5 volumes are similar to stripe sets with parity in Windows NT 4.0.

Creating multiple partitions or volumes on a single hard disk allows you to efficiently organize data for tasks such as backing up. For example, partition one-third of a hard disk for the operating system, one-third for applications, and one-third for data. Then, when you back up your data, you can back up the entire partition instead of just a specific folder.

Windows 2000 supports the NTFS, FAT, and FAT32 file systems. Use NTFS when you require a partition to have file and folder-level security, disk compression, disk quotas, or encryption. Windows 2000 and Windows NT are the only operating systems that can access data on a local hard disk that is formatted with NTFS. If you plan to promote a server to a domain controller, format the installation (boot) partition with NTFS.

FAT and FAT32 allow access by, and compatibility with, other operating systems. To dual boot Windows 2000 and another operating system, format the system partition with either FAT or FAT32. FAT and FAT32 do not offer many of the features that are supported by NTFS, for example file-level security. Therefore, in most situations, you should format the hard disk with NTFS. The only reason to use FAT or FAT32 is for dual booting.

You can access the Disk Management tool in the Computer Management console. You use the Disk Management tool to configure and manage your storage space and perform all your disk management tasks. Because the Disk Management tool is an MMC snap-in, it uses the interface, menu structure, and shortcut menus you are familiar with from other MMC snap-ins (see Figure 11.2).

Figure 11.2 The Disk Management tool

You can also create a separate console for the Disk Management tool. When you create a separate console and add the Disk Management snap-in, you have the option of focusing the tool on the local computer or on another computer for remote administration of that computer. As a member of the Administrators or Server Operators group, you can manage disks on a computer running Windows 2000 that is a member of the domain or a trusted domain from any other computer running Windows 2000 in the network.

Disk Management displays the storage system of the computer in either a graphical view or in a list. Important operating information about the disks, partitions, and volumes in your computer is contained in the Properties dialog boxes.

To view disk properties in Disk Management, select a disk, right-click it, and then click Properties. Table 11.1 describes the information in the Properties dialog box for a disk.

Table 11.1 Disk Properties

To view partition or volume properties in Disk Management, select a partition or volume, right-click it, and then click Properties. Table 11.2 describes the information that appears and the tasks that you can perform on the tabs in the Properties dialog box for a partition or volume.

Table 11.2 Partition and Volume Properties

Windows 2000 supports basic storage and dynamic storage. A disk initialized for basic storage is called a basic disk and can contain primary partitions, extended partitions, and logical drives. All versions of Microsoft Windows, MS-DOS, and Windows 2000 support basic storage. For Windows 2000, basic storage is the default, so all disks are basic disks unless you convert them to dynamic storage.

Dynamic storage creates a single partition that includes the entire disk. You divide dynamic disks into volumes, which can consist of a portion, or portions, of one or more physical disks. A dynamic disk can contain simple volumes, spanned volumes, mirrored volumes, striped volumes, and RAID-5 volumes. Dynamic storage has several advantages over basic storage: volumes can be extended to include noncontiguous space on the available disks; there is no limit on the number of volumes you can create per disk; and disk configuration information is stored on the disk and replicated to all other dynamic disks, so that one disk failure will not obstruct access to data on the other disks.

After you create partitions on a basic disk or create volumes on a dynamic disk, you must format the partition or volume with a specific file system. Windows 2000 supports NTFS, FAT, or FAT32. The file system that you choose affects disk operations. This includes how you control user access to data, how data is stored, hard disk capacity, and which operating systems can gain access to the data on the hard disk. Use the Disk Management tool to configure and manage your network storage space.