My desktop runs Ubuntu 11.04 61-bit server with LVM. I use XFCE 4 as a GUI on top of the server. Recently, I get a message on every startup which says "/dev/sda1 was not properly unmounted. Check forced". After the check completes, it now shows that hard disk is "8% contiguous". A week ago it showed 4% contiguous and now it has gone up to 8%. I get the same message irrespective of whether I shutdown from the terminal or using XFCE's shutdown button.
How serious is this issue? Is there any serious risk of data damage/corruption? Is it time to get a new hard disk?
(edit: fix spelling of contigous, was "contagious")