This means that you can improve the performance, storage limits and features of your current filesystems without reformatting and/or reinstalling your OS and software environment.
First, unmount the partition: umount /dev/sda1
Next, run a filesystem check on it to make sure it is in sane condition.
fsck.ext3 -pf /dev/sda1Enable new features of ext4 on the filesystem
tune2fs -O extents,uninit_bg,dir_index /dev/sda1Run a filesystem check. to make sure that the filesystem is now clean.
fsck -pf /dev/sda1Now edit your /etc/fstab file and replace "ext3" with "ext4" for /dev/sda1. Other options may differ for your system.
/dev/sda1 /disk ext4 defaults 0 2Try to mount your new ext4 filesystem: mount /disk