ext4 Linux File System
The ext4 filesystem has more features and generally better performance than ext3, which is showing its age in the Linux filesystem world.
Features include:
Delayed allocation & mballoc allocator for better on-disk allocation
* Sub-second timestamps
* Space preallocation
* Journal checksumming
* Large (>2T) file support
* Large (>16T) filesystem support
* Defragmentation support