I installed the latest server updates from March 13th, 2012 and upon reboot all my >2TB drives were not recognized. I am running Server 2012 Essentials on an HP EX 495.
I reinstalled the Intel RST 10.0 drivers that I had been using on the system and the problem persisted.
I then installed the Intel RST 10.1 drivers and the problem was solved.
You can find the drivers here:
http://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=20104
My old HP MediaSmart Server just keeps chugging along. Of course with the 4GB ram stick and a Quad Core running at 3.0Mhz.
Cheers,
Steve