I had a huge kernel log file of 19gb and messages file of that length as well. I attributed blame to the usb printers from HP who are extremely verbose in telling me that the usb connection has somehow got loose**.
Having dumped these files i notice that it is not showing the space as free. I reboot once a month being glad i dont have to put up with weird shit like this daily.
* a scheduler in linux ** an elephant wandered past the monkey house?