EXOFS is an object-based

Object-based file system

In computing, the term object-based file system refers to an architectural blueprint for distributed file systems. An object-based file system splits file metadata from file data and stores them on different servers...

 file system

File system

A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...

 implemented on top of an external object store.
Its name stands for "EXtended Object File System" referring to its use of ext2

Ext2

The ext2 or second extended filesystem is a file system for the Linux kernel. It was initially designed by Rémy Card as a replacement for the extended file system ....

-based metadata

Metadata

The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...

and object storage device

Object storage device

An Object-based Storage Device is a computer storage device, similar to disk storage but working at a higher level. Instead of providing a block-oriented interface that reads and writes fixed sized blocks of data, an OSD organizes data into flexible-sized data containers, called objects...

s.

Exofs was originally developed by Avishay Traeger for IBM HRL and was originally based on the ext2 file system. Since 2008, Panasas

Panasas

Panasas, Inc., is a private, multinational computer storage company based in Sunnyvale, California. It specializes in high-performance scale-out network-attached storage optimized for Linux clusters.- History :...

 develops and maintains Exofs on open-osd.org.

Exofs has been included in the mainline Linux kernel

Linux kernel

The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....

since version 2.6.30-rc1. but no Linux distribution implement this with a utility for making file systems in exofs for the current 3.0 kernel line.

External links

• http://git.open-osd.org/gitweb.cgi?p=open-osd.git;a=blob;f=Documentation/filesystems/exofs.txt;hb=refs/heads/exofs