Information Technology Reference
In-Depth Information
File systems vary in whether and how each component is implemented. Generally, more
advanced file systems have flexible filenaming rules, an efficient method of managing data stor-
age, a considerable amount of metadata, advanced attributes, and ACLs. In Chapter 1, you
reviewed some basic differences between the FAT and NTFS file systems. Next, you examine
these file systems more closely.
There are many more file systems than FAT and NTFS. For more infor-
mation on other file systems and a comparison of features, see
The File Allocation Table (FAT) file system consists of two variations: FAT16 and FAT32. FAT16
is usually simply referred to as FAT. The name “File Allocation Table” suggests the structure used
to manage data storage. FAT16 has been around since the mid-1980s, which is one of its biggest
strengths—it's well known and well supported by most OSs. FAT32 arrived on the scene with
the release of Windows 95 OSR2 in 1996.
6
A third variation of FAT, FAT12, is the original implementation of FAT
developed in the late 1970s. It was limited to use on floppy disks.
The main difference between FAT16 and FAT32 is the size of the disk partition that can be
formatted. FAT16 is limited to 2 GB partitions in most implementations (although Windows NT
permits partitions up to 4 GB). FAT32 allows partitions up to 2 TB, but in Windows 2000 and
later, Microsoft limits them to 32 GB because the file system becomes noticeably slower and inef-
ficient with larger partition sizes. This 32 GB limitation applies only to creating partitions;
Windows can read FAT32 partitions of any size. FAT16 supports a maximum file size of 2 GB,
and FAT32 supports files up to 4 GB.
The number in FAT file system names refer to the number of bits available
to address disk clusters. FAT16 can address up to 2
16
disk clusters, and
FAT32 can address up to 2
32
disk clusters. The number of disk clusters a
file system can address is directly proportional to the largest partition size
it supports.
Already, you can see that the FAT file system has severe limitations in today's computing
environment. The file size limitation alone prevents storing a standard DVD image file on a
FAT file system. The limitations are even more apparent when you consider reliability and
security requirements of current OSs. FAT doesn't support file and folder permissions for
users and groups, so any user logging on to a computer with a FAT disk has full control over
every file on that disk. In addition, FAT lacks support for encryption, file compression, disk
quotas, and reliability features, such as transaction recovery and journaling, all of which
NTFS supports.
You might think that FAT isn't good for much, especially compared with the more robust
NTFS, but FAT still has its place. It's the only file system option when using older Windows
OSs, such as Windows 9x. In addition, FAT is simple and has little overhead, so it's still the
file system of choice on removable media, such as floppy disks and the increasingly popular
flash drives. For hard drives, however, particularly on Windows servers, NTFS is unquestion-
ably the way to go.
NTFS is a full-featured file system that Microsoft introduced with Windows NT in 1993. Since
that time, its features have been expanded to help administrators gain control of ever-expanding
storage requirements. NTFS has supported file and folder permissions almost since its inception,
Search WWH ::
Custom Search