File Systems Overview

This document introduces the file systems used by major operating systems, and explains how they differ from one another.

A file system is a method of organizing files on physical media, such as hard disks, CD's, and flash drives. In the Microsoft Windows family of operating systems, users are presented with several different choices of file systems when formatting such media. These choices depend on the type of media involved and the situations in which the media is being formatted. The two most common file systems in Windows are as follows:

The NTFS file system

NTFS (short for New Technology File System) is a modern, well-formed file system that is most commonly used by Windows Vista, 7 & 8. It has feature-rich, yet simple organization that allows it to be used on very large volumes.

NTFS has the following properties:

It is recommended that NTFS be used on all media whose use is primarily with modern Windows systems. It should not be used for devices which need to be written to by Mac OS X systems or on media that is used in devices which are not compatible with NTFS.

The FAT file system

The FAT (short for File Allocation Table) file system is a general purpose file system that is compatible with all major operating systems (Windows, Mac OS X, and Linux/Unix). It has relatively simple technical underpinnings, and was the default file system for all Windows operating systems prior to Windows 2000. Because of its overly simplistic structure, FAT suffers from issues such as over-fragmentation, file corruption, and limits to file names and size.

The FAT file system has the following properties:

FAT is generally only used for devices with small capacity where portability between operating systems is paramount. When choosing a file system for a hard disk, FAT is not recommend unless you are using an older version of Windows.

NOTE: This section refers to the FAT32 file system. Some early versions of Windows 95 used the FAT16 file system, which had even more technical issues and stricter limitations. It is recommended that FAT16 is never used on any modern media.

The exFAT file system

The exFAT (Extended File Allocation Table) is a Microsoft file system that is compatible with Windows and Mac OS 10.6+. It is also compatible with many media devices such as TVs and portable media players.

exFAT has the following properties:

The HFS Plus file system

HFS (Hierarchical File System) Plus is a file system developed by Apple for Mac OS X. It is also referred to as Mac OS Extended.

HFS Plus has the following properties:

The EXT file system

The extended file system was created to be used with the Linux kernel. EXT 4 is the most recent version of EXT.

EXT4 has the following properties:

Unit Conversions

Exbibyte (EiB) - 1 exbibyte = 1.153e18 bytes = 1152921504606846976 bytes = 1,024 pebibytes
Pebibyte (PiB) - 1 pebibyte = 1.126e15 bytes = 1125899906842624 bytes = 1024 tebibytes
Exabyte (EB) - 1000000000000000000 bytes = 1e18 bytes = 1 million terabytes = 1 billion gigabytes
Terabyte (TB) - 1000000000000 bytes = 1e12 bytes = 1000gigabytes

See Also: