Differences between FAT32 and NTFS

Since they were developed over twenty years ago, the role of personal computers in our lives has drastically increased. Businesses as well as individuals use computers to store and manipulate data, produce products, and conduct business. However, when people turn on their computers and conduct their business, they probably don’t care too much about the constant reading and writing of data on the computer’s hard drive.

Over the years, hard drives and the systems used to store data on them have constantly evolved. While the two latest Windows file systems, FAT32 and NTFS, both look similar on the outside, they are really quite different, and have several advantages and disadvantages.

The Physical Disk

Before file systems can be understood, the physical disk itself must also be understood. The type of physical disk that most people are used to, is a hard drive. Also known as fixed disks, they are where computers store their operating systems, program files, and data.

Hard drives contain several platters, which are made up of either aluminum or more recently, glass. Glass is used in the newest and largest drives, because the platters can be made thinner, and they are more resistant to the heat that the drives generate.

In order for the platters to store information, they are coated with a magnetically sensitive material, primarily containing iron oxide and cobalt alloy.

The data on the platters is accessed by a head, which is moved by the head arm. There is usually one head per platter side. Figure 1 shows the primary components of a basic hard drive.

Information stored on the hard drive is divided up into many distinct areas on the platters. Tracks, sectors, and cylinders are what define these areas.

A track is a ring around a platter, containing information. Tracks on each platter line up with each track on the platter above or below. Each set of tracks that are identically positioned above or below each other are called cylinders.

The final way that the information in hard drives is divided is into sectors.

Sectors on a platter can be thought of as slices of a pie. Sectors are necessary,

because there would otherwise be too much information in each track (“Hard

Drives”).

File System Basics

Operating systems need a way to manage the data that is stored on a hard drive. This is where file systems come into play. Just as people organize their CD or DVD collections for retrieval at a later date, operating systems need a way to organize files for retrieval.

File Attributes

A file can be thought of as an abstract data type. The attributes that most operating systems would give to a file include the following:

•       Name – This is the attribute of the file that computer users are used to seeing on a regular basis. It is simply the symbolic name of the file.

•       Type – The type of a file defines what operations can be performed on it.

Types of files include executable, text, image, etc. The operating system usually associates a certain action with each type of file (e.g. open with Microsoft Word, or execute).

•       Location – This is a pointer to the file on the device on which it resides

(e.g. a hard disk drive).

•       Size – This is the size of the file, usually in bytes, words, or blocks.

•       Protection – This is usually specified by a user, and defines the level of access that other users can have. Different levels may include reading, executing, writings, etc.

•       Time, date, and owner – Most operating systems usually keep track of a file’s creation, last modification, and last use date and time. Certain operating systems (such as Windows NT) also keep track of who created the file (Silberschatz 338). 

File Operations

As an abstract data type, there are several different operations that can be performed on a file. These operations are provided by the operating system as system calls. The basic file operations include:

•       Creating – In order to create a file, the operating system must allocate the proper amount of storage space. Then, an entry into the file’s directory must be made, in order for a user to see that the file is in that directory.

•       Writing – To write to a file, the operating system controls a write pointer, which specifies the next location to write to. Whenever a write occurs, this pointer must be updated.

•       Reading – Much like writing, the operating system controls a read pointer, which specifies the next location to read from. Once a read occurs, the read pointer is updated.

•       Deleting – The operating system first locates the proper file to delete. Once it is found, the space associated with the file is freed, and its entry in the directory is removed (Silberschatz 339).