Chapter 9: Hard Disks and Floppy Disks^193
File Systems
Operating systems use a file system to manage the allocation and utilization of the disk
storage. The high-level format process creates the operating system’s file system, copies
the operating system to the primary partition, and builds the management tables and
files, such as the File Allocation Table (FAT). Each operating system uses afilesystem, like
the FAT, to track the usage of the disk and the placement of files. Table 9-3 lists the names
of the file systems used by some of the more popular operating systems.
Here is a brief description on the file systems referenced in Table 9-3: FAT (File Allocation Table) This file system, also called FAT16, is used by
DOS and Windows 3.xto place and locate files and the pieces of fragmented
files on the hard disk.
HPFS (High-Performance File System) Many later file systems, such as
NTFS, evolved from HPFS, which features better security, reliability, speed,
and efficiency than FAT.
UNIX File System/Linux File System The Unix and Linux file systems use
a branching-tree file structure that emanates from a root directory, which can
have an unlimited number of subdirectories and sub-subdirectories, and so on.
VFAT (Virtual File Allocation Table) VFAT is available in Windows for
Workgroups and Windows 95. It actually serves as an interface between
applications and the physical FAT. Its most outstanding feature is that it was
the first Windows file system to allow long filenames.
FAT32 (32-bit FAT) This is the file system in later releases of Windows 95
and in Windows 98. It supports larger disk capacities (up to two terabytes)
and uses a smaller cluster size to produce more efficient storage utilization.
NTFS (NT File System) NTFS is one of the two file systems used by the
Windows NT operating system (the other is the standard FAT file system for
backward compatibility purposes). NTFS uses transaction logs to help recover
from disk failures; it has the ability to set permissions at the directory or
individual file level and allows files to span several disks or partitions.Disk Space Requirements
In today’s world of downloadable music, graphics, interactive media, and disk-consuming
software, it can be hard to know just how much disk space is enough on a system. Table 9-4
lists the disk space requirements for some of the more popular graphics programs.