Re: MS Exchange
MSCS on Dells was always a headache for me... but they were on en EMC/Brocade SAN.
We (work) put in a nice HP SuperDome cluster in for NASA last year... seems to be working great!
Wish I could say the same for another customer with Veritas CS... painful, painful, painful. But they are trying to run it between nodes on a SONET ring several hundred km away. EMC SRDF works great over that tho.
But, the all-time winner for clusters has to be OpenVMS. Digital (R.I.P.) had that chit nailed. Even today, there are systems out there with cluster uptimes in the DECADES.