File Systems

A file system is the method used by an OS to manage the data on a drive. To make different drive or partitions, we use FDISK command. To make tracks & sectors on a drive, we use FORMAT command. The OS uses only one file system for an entire logical drive.

Types of file system

CDFS : - It is Compact Disk File System. It is read only and used to read the contents of CD – ROM. It is supported by all OS. In some OS we need to install it like in DOS but in OS like 9x it automatically installed.
UDF : - It is Universal Disk Format and read only file system used to read the contents of DVD.
HPFS : - It is High Performance File System which comes only in Win NT 3.5.
FAT 16 : - FAT is File Allocation Table and 16 means it used 16 bits or 2 Bytes to make each entry. It is supported by all OS so it is also called universal file system.
FAT 32 : - This f/s use 32 bits to make each entry. But it is not supported by DOS, Win 95 and Win NT.

Difference between FAT 16 & FAT 32

FAT 16

1. Hard Disk Size
in Win 98 à Up to 2GB
in Win NT/2k à Up to 4GB
2. Cluster size
in 2GB à 32KB
in 4GB à 64KB
3. It is slow in speed.
4. It is supported by all OS.
FAT 32

1. Hard Disk Size
in Win 98 à Up to 2TB
in Win NT/2k à Up to 32GB
2. Cluster size
in 8GB à 4KB
in 16GB à 8KB
3. It is fast in speed.
4. It is don't supported by DOS, Win 95,
Win NT.

Cluster size : -
It is one or more sectors that constitute the smallest unit of space on a disk for storing data also called FAT, files are written to a disk as groups of whole clusters.
Mainly we use FAT32, because of small cluster size to reduce the wastage of HD space called slacks . To see the cluster size, we use CHKDSK command.
In some cases, like in installation of win 2k, system does not ask about format with FAT 16 or FAT 32. Then it checks the partition size, if the size is less than 4GB, it format with FAT 16 otherwise with FAT 32.

NTFS : - It is New Technology File System.
In Win NT 4.0 à NTFS 4.0
In Win NT 5.0 à NTFS 5.0
NOTE: - Floppy can not be format in NTFS file system, because in NTFS it requires 25% of partition total space for directory overhead.

Features of NTFS
There are many hot features of NTFS file system over FAT. Comparison of NTFS, FAT 32 and FAT 16 in case of Win 2k is displayed on next page: -

Feature

1. File level security
2. Speed to access files
3. Huge partition
4. Compression (file level)
5. Long file name
6. Local security
7. Cluster size
8. POSIX support
9. Support Macintosh files
10. Volume set extension
11. Hot fixing
12. Recoverable f/s
13. Encrypting f/s
14. Disk Quota
NTFS

v (12 permissions)
v
16EB
2:1
v
v
64 bits
v
v
v
v (chkdsk)
v
v
v
FAT 32

X
v
32GB
X
v
X
32 bits
X
X
X
X
X
X
X
FAT 16

X
X
4GB
X
X
X
16 bits
X
X
X
X
X
X
X

Compression: - It is a feature of NTFS. We need not to uncompress the folder to open like Win Zip. But the speed goes slow due to background process of uncompressing. When we copy a file from FAT to NTFS, it automatically compressed. When we copy a file from NTFS to FAT, it automatically uncompressed. We can do it with a file, sub-directories, directories and drives. The color of compressed folder is changed in blue, if there is check on ‘Display compressed files with alternate color' in the view tab of ‘folder options'.
POSIX support: - POSIX is Portable Open System Interface. There is case sensitive in LINUX. But in window case is not sensitive. But if we install Win 2k with NTFS f/s then it can open LINUX files.
Support Macintosh files: - Apple computer have different h/w devices and files stored in different format. But Win 2k with NTFS f/s can open Macintosh files on a network.
Volume set extension: - In Win 2k with f/s NTFS we can extend the size of partition without deleting any partition.
Hot fixing: - In FAT f/s we can only check error with the use of SCANDSK command but in NTFS we can check and fix errors or bad sectors of hard disk.

Use in Different OS
All the OS does not support all f/s. The table of support ness of f/s of each OS is given below: -

OS
FAT 12
FAT 16
VFAT
FAT 32
NTFS
CDFS
DOS
v
v
X
X
X
v
Win 95
v
v
v
X
X
v
Win 98
v
v
v
v
X
v
Win ME
v
v
v
v
v
v
Win 2k
v
v
v
v
v
v
Win NT
v
v
v
X
v
v

Converting FAT f/s to NTFS

There are fewer features in FAT f/s rather than NTFS. We can convert FAT f/s to NTFS by using the following command on Command Prompt.
CONVERT :/FS : NTFS
But we can not convert NTFS partition to FAT. It can corrupt the data.

Delete a partition

There is no problem to delete FAT 16/ FAT 32 f/s partition. We can delete it with FDISK command on Command Prompt.
We cannot delete a NTFS partition with FDISK. To delete a NTFS partition, there are many options.
• Disk Manager
• Bootable Win 2k CD-ROM
• Computer Management
• By FDISK, we can delete only primary NTFS partition not logical.