In my limited tests, this seems to make a small but noticable
difference, improving the performance of some straightforward
read operations by a little over 10%.
For more information see:
http://kbase.redhat.com/faq/docs/DOC-5428
# Improve virtio-blk performance (RHBZ#509383).
for f in /sys/block/vd*/queue/rotational; do echo 1 > $f; done
+# http://kbase.redhat.com/faq/docs/DOC-5428
+for f in /sys/block/[hsv]d*/queue/scheduler; do echo noop > $f; done
+
# Keep these to enhance the usefulness of debug output.
ls -l /dev
cat /proc/mounts