, X 4 or (fourth extended filesystem) (briefly, ext4) is a file system-based journal that as the new version for the file system ext3, is introduced. the ext4 file system, the current default Linux kernel.

the system file first as a series of plugin compatible for System, File, former, i.e., ext3 was born, that a lot of this by the company Cluster File Systems for use in File System Lustre is a file system for computers, cluster (cluster) between the years 2003 to 2006 was developed, who its main purpose, storage limits, and add to the speed and efficiency of File System previous. Developers Linux of accept, the plugin written as part of the file system ext3, with the justification that the new plugin causes instability of the file system can be significant, but they instead decided that a branching of the code of ext3, there have been, and all the changes made, along with the other additional functionality in the new code apply and they file system the new to come there to ext4 called.

version of the introductory file system ext4, on 11 October 2008 to codes Linux version 2.6.19 were added, But codes final that this file system as a file system, stable, introduced in version 2.6.28 Linux was included. Version 2.6.28, along with file system new ext4 in December 2008, the publication found that in the new version of the file system ext4 as the file system of the proposed Linux was introduced. In 2010, Google announced that the structure of the storage of information in the to ext4, will change this company also, file system ext4 to replace the file system of YAFFS, on Android operating system.