Managing and Maintaining Physical and Logical Devices

Windows Server 2003 supports two types of physical disk configurations: basic and dynamic. A single physical disk must be one type or the other; however, you can intermingle the physical disk types in a multiple-disk server.

Basic Disks

When a new disk is installed in Windows Server 2003, it is installed as a basic disk. The basic disk type has been used in all versions of Microsoft Windows since version 1.0, OS/2, and MS-DOS. This allows a basic disk created in Windows Server 2003 to be recognized by these earlier operating systems. A basic disk splits a physical disk into units called partitions. Partitions allow you to subdivide your physical disk into separate units of storage. There are two types of partitions: primary and extended. On a single physical hard disk you can have up to four primary partitions, or three primary partitions and an extended partition. The basic disk is the only type supported in versions of Windows prior to Windows 2000.

Dynamic Disks

Dynamic disks were first introduced in Windows 2000 and are the preferred disk type for Windows Server 2003. Unlike a basic disk, a dynamic disk is divided into volumes instead of partitions. Although a clean installation of Windows Server 2003 will create a basic disk by default, any additional disks can be added as basic or dynamic disks. In addition, after the initial installation, the basic disk can be converted to a dynamic disk.

Unlike basic disks, which use the original MS-DOS-style master boot record (MBR) partition tables to store primary and logical disk-partitioning information, dynamic disks use a private region of the disk to maintain a Logical Disk Manager (LDM) database, which contains the volume types, offsets, memberships, and drive letters of the volumes on that physical disk. The important characteristics of dynamic disks are summarized in Table 1.

Table 1. Dynamic Volume Types

Volume Type	Number of Disks	Configuration	Fault Tolerance
Boot	N/A	The volume that contains the %Systemroot% files (usually C:\Windows).	N/A
System	N/A	The volume that contains the Ntdetect.com, Ntldr, and Boot.ini files (usually C:\).	N/A
Simple	1	A single region or multiple concatenated regions of free space on a single disk.	None.
Spanned	2 to 32	Two or more regions of free space on 2 to 32 disks linked into a single volume. Can be extended. Cannot be mirrored.	None.
Striped	2 or more	Multiple regions of free space from two or more disks. Data is evenly interleaved across the disks, in stripes. Known as RAID Level 0.	None.
Mirrored	2	Data on one disk is replicated on the second disk. Cannot be extended. Known as RAID Level 1.	Yes, with maximum capacity of the smallest disk.
RAID 5	3 to 32	Data is interleaved equally across all disks, with a parity stripe of data also interleaved across the disks. Known as RAID-5 or striping with parity.	Yes, with maximum capacity of the number of disks minus one. (If you have 5 100GB disks, your volume would be 400GB).

• A dynamic disk cannot be read by other operating systems in a dual boot configuration.

• Several utilities can help manage the disk partitions:

  • CHKDSK.EXE Command-line utility that verifies and repairs FAT or NTFS formatted volumes.

  • CLEANMGR.EXE a.k.a. Disk Cleanup, a GUI utility that deletes unused files.

  • DEFRAG.EXE a.k.a. Disk Defragmenter, a command-line utility that rearranges files contiguously, recapturing and reorganizing free space in the volume. Optimizes performance.

  • DFRG.MSC a.k.a. Disk Defragmenter, a GUI utility that performs the same actions as DEFRAG.EXE.

  • DISKPART.EXE A command-line utility that can run a script to perform disk-related functions. DISKPART's nearest GUI counterpart is the Disk Management utility.

  • FSUTIL.EXE A command-line utility that displays information about the file system and can perform disk-related functions.

Unlike Windows NT 4.0, Windows Server 2003 does not support the creation or use of any of these configurations on a basic disk. If any of these volumes are present on a basic disk in a server that is upgraded to Windows Server 2003, or if they are added after Windows Server 2003 is installed, they will no longer be accessible.

File Systems

Two main file systems are recognized by Windows Server 2003:

• File Allocation Table (FAT) Windows Server 2003 is able to read partitions formatted in two versions of FAT: the 16-bit version (FAT16), supported by early versions of MS-DOS, and the 32-bit version (FAT32), first introduced with Windows 95 OEM Service Release 2 (OSR2). For FAT16 partitions, the maximum size is 4GB. In theory, FAT32 partitions support a maximum size of 2,047GB. However, there is a 32GB limitation on creating FAT32 partitions in Windows Server 2003.

• The NT File System (NTFS) NTFS is designed to provide a high-performance, secure file system for Windows Server 2003. It also supports selective file, folder, and volume compression or encryption and auditing. In addition, NTFS supports security assigned at the file, folder, or volume level.

NTFS Compression

Native file and folder compression is one of the many benefits of using NTFS. NTFS compression and EFS encryption are mutually exclusive. That is, you cannot both compress and encrypt a file or folder at the same time. Because NTFS compression is a property of a file, folder, or volume, you can have uncompressed files on a compressed volume or a compressed file in an uncompressed folder.

In addition, several rules apply when you move or copy compressed files and folders. The possible outcomes of moving or copying NTFS-compressed files or folders are as follows:

• Moving an uncompressed file or folder to another folder on the same NTFS volume results in the file or folder remaining uncompressed, regardless of the compression state of the target folder.

• Moving a compressed file or folder to another folder on the same volume results in the file or folder remaining compressed after the move, regardless of the compression state of the target folder.

• Copying a file to a folder causes the file to take on the compression state of the target folder.

• Overwriting a file of the same name causes the copied file to take on the compression state of the target file, regardless of the compression state of the target folder.

• Copying a file from a FAT folder to an NTFS folder results in the file taking on the compression state of the target folder.

• Copying a file from an NTFS folder to a FAT folder results in all NTFS-specific properties being lost.