How To Convert Existing ext3 non-root FileSystem to ext4 FileSystem

Any existing Ext3 filesystem can be migrated to Ext4 with an easy procedure (as long as you are converting a filesystem that can be unmounted and which is non-root) which consists in running a couple of commands.

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/sda1

Enable new features of ext4 on the filesystem

tune2fs -O extents,uninit_bg,dir_index  /dev/sda1

Run a filesystem check. to make sure that the filesystem is now clean.

fsck -pf /dev/sda1

Now 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 2

Try to mount your new ext4 filesystem: mount /disk