Filesystem

A filesystem is a subsystem of a UNIX system. It is built on top of secondary storage devices but not limited to that and can also be built on top of primary storage devices (RAM) or be an entirely virtual filesystem. A UNIX system cannot operate without bootstrapping itself and programs from the filesystem.

List of filesystems available in UNIX and UNIX-like Operating Systems

Unix File System (ufs)

Most UNIX'es have the ufs filesystem it is derived from the Berkeley ffs filesystem.

Berkeley Fast File System (FFS)

The ffs filesystem was written at UCB by Marshall Kirk McKusick for 4.2BSD. It is still widely used in the BSD family of Operating Systems.

Memory File System (mfs)

Proc File System (/proc)

Device File System (devfs)

Union File System (unionfs)

Kern File System (kernfs)

Bind File System (bindfs)

Null File System (nullfs)

Ext2 File System (ext2fs)

Ext3 File System (ext3fs)

Reiser File System (ReiserFS)

X File System (xfs)