Filesystems

Linux

Filesystems

Windows Filesystems

Early versions of Windows, such as Windows 3.1 and Windows 95, used the FAT16 filesystem, also called MS-DOS filesystem.

FAT 32 was introduced in Windows 95b, and was used in following versions, such as Windows 98 and Windows ME.

NTFS was introduced in Windows NT. Windows XP could be installed on FAT32 or NTFS. Recent versions of Windows use NTFS.

Limitations of FAT filesystems

FAT 16 is limited to 2 gb partitions (4 gb with certain operating systems, but not widely supported), so it is normally only used on drives of 2 gb or less.

FAT 32 is limited to 4 gb files.

If you want to save large files, such as entire DVDs, you cannot save them on FAT 16 or FAT 32 filesystems.

NTFS and Linux filesystems do not have those limitations.

Linux Filesystems

There are a number of Linux filesystems. The most commonly used is Ext3. Some recent versions of Linux use the Ext4 filesystem. Expect this to become the most commonly used Linux filesystem in the future.

Linux Filesystems Permissions

In Linux filesystems, every file and directory belongs to an Owner and Group, and has Permissions. This increases the security of Linux operating systems, as files cannot be modified without appropriate permissions. Windows filesystems do not have this feature, and are not as secure.

For more information, see File Ownership, and File Permissions.

Journalling Filesystems

When a non-journalling file system is used, the computer writes a file to the drive, then writes a record of what it has written. If a power failure or malfunction occurs before it has finished, the computer may have something partly written, but not have a record of what it is. As a result, the drive may contain lost fragments of files.

If a Journalling filesystem is used, the computer writes in a journal what it intends to write, then writes the file, and when it has finished, writes a record of what it has written. As a result, if a power failure or malfunction occurs before it has finished, there is a record of what this partly written file is. If the complete file has been written, but not the record, the computer corrects the record. If the complete file has not been written, the computer restores the file to how it was last saved before the power failure or malfunction. As a result, the drive does not contain lost fragments of files.

Examples of filesystems which are not journalling filesystems include Fat16, FAT32, and the Ext2 Linux filesystem.

Examples of filesystems which are journalling filesystems include Ext3 and Ext4.

USB Drives and Journalling Filesystems

USB drives can only be written to a limited number of times (normally many thousands), and then they will not work.

Some people prefer to use non-journalling filesystems on USB drives so less is written, and the USB drive will last longer.

Other people prefer to use journalling filesystems on USB drives, to avoid having lost files.

Newer USB drives tend to last longer than older USB drives.

Other factors make a much greater difference to the life of a USB drive, such as not having a swap file or partition on a USB drive. A swap file or partition on a USB drive will greatly shorten its life.

Most newer operating systems are designed to avoid writing unnecessarily to USB drives, so they last longer.

If You Prefer a Non-Journalling Filesystem

If you want to use a non-journalling filesystem on a USB drive so it will last longer, you can use FAT16, Fat32 or Ext2.

If the Ext2 filesystem is used, every file and directory belongs to an Owner and Group, and has Permissions, reducing the likelihood of filesystem corruption.

Linux on FAT Filesystems

Most USB drives 2 gb or less come formatted with the FAT16 filesystem. Most USB drives larger than 2 gb come formatted with the FAT32 filesystem.

Most Linux distributions can only be installed on a Linux filesystem.

A few Linux distributions have been adapted so they can be installed on FAT16 or FAT32 filesystems on USB drives.

USB drives can also be formatted with Linux filesystems, before installing Linux.

Advantages of Installing Linux on a FAT16 or FAT32 Filesystem

When installed on a FAT16 or FAT32 filesystem, files can be accessed on the USB drive while using Windows (without installing a program for this).

Disadvantages of Installing Linux on a FAT16 or FAT32 Filesystem

Linux operating systems are designed to be installed on Linux filesystems. A few have been adapted so they can be run on FAT16 or FAT32 filesystems. In certain situations, malfunctions may occur, as they have not been adapted 100%.

In a Linux filesystem, every file and directory belongs to an Owner and Group, and has Permissions. This is not the case with FAT16 and FAT32 filesystems. As a result, operating systems on FAT16 and FAT32 filesystems are more likely to become corrupted.

If you want to save large files, such as entire DVDs, you cannot save them on FAT 16 or FAT 32 filesystems.

Accessing Other Filesystems

While using Linux or Windows, files can be accessed in FAT16 and FAT32 filesystems.

Most Linux Distributions include programs for accessing files in NTFS.

While using Windows, files cannot be accessed in Linux filesystems. Programs can be installed in Windows to access files in Linux filesystems.

NTFS

Linux cannot be installed on other filesystems, such as NTFS (without major modifications, which are beyond the ability of most users).

Changing Filesystems

Partitions and filesystems may be modified using one of the Live CDs for Partitioning.

A USB drive can also be reformatted to FAT 16 or FAT 32 using Windows.

Older Computers

The BOIS in older computers cannot be set to start an operating system from a USB drive.

Swap Partition

A computer uses a swap partition or swap file like extra RAM.

If you install Linux on a USB drive, do not make a swap partition or swap file on the USB drive, as it will greatly shorten the life of the USB drive. If Linux is installed on the hard drive, it will have a swap partition, and Linux on the USB drive will use it. If there is no swap partition, make one on the hard drive.

< If a Computer Won't Start from a CD, DVD or USB Drive

Partitioning >