Ext3 File system
The ext3 filesystem is a journaling extension to the standard ext2 filesystem on Linux. Journaling results in massively reduced time spent recovering a filesystem after a crash, and is therefore in high demand in environments where high availability is important, not only to improve recovery times on single machines but also to allow a crashed machine’s filesystem to be recovered on another machine when we have a cluster of nodes with a shared disk. This talk will describe the ext3 filesystem, both its design goals and its implementation. It will explain some of the challenges involved in adding journaling in a way which is completely compatible with existing ext2 filesystems (it is possible to migrate existing ext2 filesystems to ext3 and back again), and will cover the architecture of the implementation, which involves a completely new, generic block device journaling layer in the kernel.
Though comparatively, Ext3 file system is slow to mount and unmount than JFS,XFS, it actually restores hard disk space the best when you want to format the hard disk. Ext3 is native to Linux.