bosun-monitor/scollector — pull request #144 by lukaspustina (2014-11-19 12:15:34+00:00)
Title: ios_in_progress should be Gauge instead of Counter

According to http://www.mjmwired.net/kernel/Documentation/iostats.txt#81 the value represents the currently IO operations in flight. So it not a counter. Seems like a copy&paste mistake to me.
If you force the rate type to Gauge in Bosun's UI, the metric suddenly makes sense :)