Posted Feb 5, 2010 10:41 UTC (Fri) by alex (subscriber, #1355)
Parent article: Improving readahead
One pathological case I cam across recently is the handling of RRD files.
Updates to RRD files tend to be to the header and one other block in the
file. Most of the time any readahead is a complete waste of time from an
efficient I/O point of view.
Do the readahead heuristics handle the case where the readahead is never
actually used by the process? Just turning down the global readahead knob is
a rather clunky solution as I'm sure it's useful for a lot of other cases
(spooling programs up for example).