This notification informs you of the current status of fragmentation on a partition. No action is required to fix this.
However, non-contiguous is not necessarily a valid measure of fragmentation, especially if you have a lot of bad blocks.
You can defrag with e2defrag, if you have it installed. If not, it may be on your distribution CD or you can always download the tarball.
Read the documentation carefully
run defrag on a mounted filesystem.