I managed to be able to see what i wanted in my NetApp SAN using the universal device poller chart as you suggested, thanks.
Screenshot: http://www.myupload.dk/v/c45ez3.png
Now I presume I can set-up an alarm by this by using "status description" change in Alert Manager? Or maybe you have a better suggestion as how to do this?
Screenshot 2: http://www.myupload.dk/v/c4c8g5.png
//Anders