Sams Teach Yourself MCSE Windows NT Server 4 in 14 Days
(Publisher: Macmillan Computer Publishing)
Author(s): David Schaer, et al
ISBN: 0672311283
Publication Date: 12/15/97

Chapter 5
Managing Local File Systems

by David Schaer and Theresa Hadden

5.1. Overview

The choice of which file system or systems to use on a computer will be determined by many factors. These factors include the role of the computer, available disk space, desired disk performance, and whether you have a dual-boot machine.

5.1.1. Objectives

Operating systems use file systems to store and retrieve files in an ordered fashion. NT 4.0 supports three file systems: FAT, NTFS, and CDFS. In addition to choosing a file system, you must also understand how to manage your hard disk partitions. This chapter covers the following topics:

•  Choice of file system

•  Configuring fault tolerance

•  Understanding the role of RAID and volume sets

5.1.2. Fast Facts

The following list of facts is a concise picture of the information presented in this chapter. It acts as both an overview for the chapter and as a study aid to help you do any last-minute cramming.

•  NT Server supports FAT, NTFS, and CDFS file systems.

•  NTFS is the only file system to provide local security.

•  The default Access Control List (ACL) is initially set to Everyone Full Control.

•  FAT is the only file system accessible to DOS, Windows 95, OS/2, and NT.

•  FAT does not provide any form of local security.

•  Long and short filenames can be created on both FAT and NTFS when NT is the active operating system.

•  Compression can be applied only to files and directories on NTFS volumes.

•  RISC-based computers require a minimum of a 2MB FAT system partition.

•  Intel-based machines can run with NTFS as the only file system.

•  No Access invalidates any other rights that a user is granted individually or through group membership.

•  When files are moved between folders on the same NTFS partition they maintain their security settings (ACL).

•  By default, compressing a directory compresses the files within it but not the subdirectories.

•  The HPFS file system is not supported in NT 4.0.

•  The Convert.exe utility converts only from FAT to NTFS. It is a one-way procedure.

•  To convert the system or boot partition you must schedule the conversion for the next reboot of the system.

•  Implementing file-level security or compression on FAT is not supported.

•  LIST is the minimum set of NTFS permissions required to share a directory.

•  DIR /X displays both the long and short filenames.

•  A single physical disk can have a maximum of four partitions.

•  Only one partition can be marked as active. Only primary partitions can be set as active.

•  Partitions can be formatted as either FAT or NTFS.

•  Up to four logical drives can be created within a single extended partition.

•  Only one extended partition can exist per physical disk.

•  The Disk Administrator is the major NT tool for managing disks and partitions.

•  Large cluster sizes are a benefit when using large files.

•  A 2TB partition is the theoretical maximum size with NTFS.

•  When you change the assigned drive letter for a volume or CD-ROM the change takes place immediately.

•  Configuration changes must be committed before you format new partitions.

•  Volume sets do not increase performance.

•  Volume sets can be extended only if they are formatted as, or converted to, NTFS.

•  Volume sets can reside on 1 to 32 physical disks.

•  The system or boot partitions cannot be part of a stripe or volume set.

•  When you lose a single disk containing any portion of a volume set the data is lost across the entire volume set.

•  Stripe sets cannot be extended.

•  Stripe sets must be created from equal amounts of free space from two or more physical disks.

•  Stripe sets without parity can be created from portions of 2 to 32 physical disks; stripe sets with parity require at least 3 physical disks to a maximum of 32.

•  Stripe sets provide the best read/write disk performance.

•  Stripe sets without parity do not provide fault tolerance.

•  Data in stripe sets is written 64KB at a time.

•  The disk configuration can, and should, be saved to floppy disk.

5.2. File System Basics

It is important not to confuse file systems with operating systems. Not all file systems are supported by all operating systems. For example, the DOS and Windows 95 operating systems support only the FAT file system, and OS/2 supports FAT and HPFS. The NTFS file system is supported only by the NT operating system.

Don’t confuse file system with operating systems. FAT is the only file system that is supported across DOS, Windows 95, OS/2, and NT.

Applications running in environment subsystems under NT will be able to access files on FAT, NTFS, and CDFS. When you format a partition from within NT it defaults to the FAT file system unless you specify otherwise.

5.2.1. Sometimes FAT Is Good

You might have heard people say that a little fat is a good thing. The same can often be said of a little FAT, or more specifically, a little FAT partition for storing the NT boot and system files. Formatting the boot and system partitions with FAT in order to simplify the repair of corrupted files is sometimes advantageous.

FAT is the only file system that is accessible to DOS, Windows 95, NT, and OS/2. By booting from a DOS system disk you can access the FAT partitions that were formatted under OS/2 and NT. This is one of the reasons why the FAT file system is not recommended for partitions that require high security levels.

When compared with NTFS, the FAT file system structure has very little overhead. If none of the special features of NTFS are required, FAT is recommended for partitions of 400MB or less. By design, a FAT volume cannot exceed 4GB.

Although a DOS-based workstation can only access the FAT file system locally the file system in use at the file server can be NTFS.