#14 0.5.0-pre5 disk-io reports cummulative blocks, not io rate

[R Tsang]

disk-io module reports cummulative blocks, not io rate
in HotSaNIC 0.5.0-pre5

With version 0.4.0, rrd is updated with the difference
of two readings from /proc/stat disk_io (compares
last.dat). However the latest in the files repository
(0.5.0-pre5/modules/diskio/platform/linux.pm) doesn't
calculate the difference! It just dumps the /proc/stat
reading to RRDs::update. So the graph is incorrect.
It shows cummulative disk activity over time, but
should be showing instantaneous rate of disk activity.

This is a critical bug in the disk_io module. I also
checked the latest CVS snapshot as of July 29 2004 and
it doesn't appear to have been fixed yet. Thanks.