Greetings! Just a brief plug for Debian here -- we've been using it
on our commercial cluster for many years and across several hardware
upgrades, and, after the initial installation, never futzing with the
software by hand other than 'apt-get install' and/or 'apt-get
dist-upgrade'! We're literally running the 'same installation'
automatically upgraded via apt through at least 3 or 4 Debian release
generations. And the quantity of parallel software available 'out of
the box' is enormous! I'll never forget the day I could just 'apt-get
install scalapack-lam-dev' and diagonalize huge matrices across the
cluster with hardly a hitch. As for the initial installation, some
people like FAI, though I have never tried it myself, as I've only had
to install once, and that was somewhere around 1995 ....
Take care,