Before you can store data on a physical disk, you
must prepare the disk for use by partitioning its space, assigning a
drive designator, and formatting the resulting partitions or volumes.
Although basic disks can have up to four primary partitions—or three
primary partitions and one extended partition, with one or more logical
drives in the extended partition—dynamic disks can have an unlimited
number of volumes.
After partitioning a disk, you must assign each
partition or volume a drive designator. The drive designator can be a
letter or a path. You use drive letters to access file systems in
various partitions on physical drives. Generally speaking, the drive
letters A through Z are available. However, the drive letter A is
usually assigned to the system's floppy drive. If the system has a
second floppy drive or another removable media drive, such as a Zip
drive, the letter B is usually assigned to it (or unassigned
otherwise). The drive letter C is usually assigned to the first
partition or volume created on Disk 0. The drive letter D is usually
assigned to the first CD-ROM or DVD-ROM. Thus, on most systems, the
drive letters E through Z are available. If you need additional
volumes, you can create them using drive paths.
drive path is set as a folder location on an existing local disk. For
example, you could mount additional drives as C:\Docs1, C:\Docs2, and
C:\Docs3. Drive paths can be used with basic and dynamic disks. The
only restriction for drive paths is that you mount them on empty
folders that are on NTFS-formatted local disks.
Formatting a partition or a volume sets the file system
that will be used and creates the necessary file structures. Generally
speaking, you can format a partition or a volume as FAT, FAT32, or
NTFS. There are restrictions and requirements for the use of each,
FAT is a 16-bit file system designed to be used with
volume sizes of up to 4 GB and is also referred to as FAT16. FAT uses a
boot sector that stores information about the disk type, the starting
and ending sectors, and the active partition. FAT gets its name from
the file allocation table it uses to track the cluster locations of
files and folders. There is a primary table and a duplicate table. The
duplicate is used to restore the primary table if it becomes corrupted.
FAT also has the capability to mark clusters (sections of disk
containing data) as unused, in use, bad, or reserved. This helps to
make FAT a fairly robust file system. FAT is best with volumes of 2 GB
or less, and it has a maximum file size of 2 GB. FAT can be used with
floppy disks and removable disks.
FAT32 is a 32-bit version of FAT16, with some
additional features and capabilities. Like FAT16, FAT32 uses a primary
and a duplicate file allocation table. FAT32 can also mark clusters as
unused, in use, bad, or reserved. FAT32 can also be used with floppy
disks and removable disks. Unlike FAT16, FAT32 has a minimum volume
size of 33 MB, a maximum volume size of 32 GB, and a maximum file size
of 4 GB. This means FAT32 can be used with considerably larger
partitions and volumes than FAT16.
It is important to note that the 4-GB maximum
file size limitation for FAT32 is specific to Windows 2000 and later
versions of Windows. Using FAT32, some earlier versions of Windows can
create volumes of larger size, as can other operating systems.
NTFS is very different from FAT16 and FAT32. Instead of
using a file allocation table, NTFS uses a relational database to store
information about files and folders. This database is called the Master
File Table (MFT), and it stores a record of each file and folder on a
volume as well as additional information that helps to maintain the
volume. Overall, the MFT makes NTFS much more reliable and recoverable
than either FAT16 or FAT32. This means that NTFS can recover from disk
errors more readily than FAT16 and FAT32 can, and that NTFS generally
has fewer disk problems.
NTFS has a maximum volume size of 2 TB (terabytes, or
trillion bytes) or higher (depending on disk configuration) and a
maximum file size that is limited only by the volume size. Although you
can't use NTFS with floppy disks, you can use NTFS with removable
disks. Additionally, unlike FAT16 and FAT32, which have limited
security features (namely that you can mark a file only as read-only,
hidden, or system), NTFS has advanced security (meaning that you can
use permissions to set very specific file and folder access). NTFS supports many other advanced features as well, including compression, encryption, and disk quotas.
Several versions of NTFS have been implemented.
NTFS 4 was first available with Windows NT. NTFS 5 was first available
with Windows 2000. NTFS 5.1 was first available with Windows XP.
Because most current computers have NTFS 5 or later, I focus on NTFS 5
and later in this book. It is also worth noting that if you upgrade a
system with a version older than the current version, you are given the
opportunity to convert existing NTFS volumes to the latest version
during installation. In most cases, you want to do this because it
ensures support for the latest NTFS features.