Description:

The e4fsprogs package contains a number of utilities for creating,
checking, modifying, and correcting any inconsistencies in the
fourth extended (ext4) filesystem. E4fsprogs contains
e4fsck (used to repair filesystem inconsistencies after an unclean
shutdown), mke4fs (used to initialize a partition to contain an
empty ext4 filesystem), debugfs (used to examine the internal
structure of a filesystem, to manually repair a corrupted
filesystem, or to create test cases for e4fsck), tune4fs (used to
modify filesystem parameters), and most of the other core ext4fs
filesystem utilities.

Please note that "e4fsprogs" simply contains renamed static binaries
from the equivalent upstream e2fsprogs release; it is packaged this
way for Red Hat Enterprise Linux 5 to ensure that the many changes
included for ext4 do not destabilize the core e2fsprogs in RHEL5.

You should install the e4fsprogs package if you need to manage the
performance of an ext4 filesystem.