MegaCLI monitoring doesn't work for the new generation of Dell PERC H750 controllers.
Support in a private repo for the binaries is roll(ing) out via the parent of this task.
This task should track the fix for icinga monitoring. An example of the bad monitoring check can be viewed for dumpsdata1007, which has virtual disks but megacli reports none: https://icinga.wikimedia.org/cgi-bin/icinga/status.cgi?host=dumpsdata1007