hello
how can i run, example gfortran parallel on rocks clusters. because as of now gfortran is compiling only on single node, if this be the case then all the nodes are useless...
what commands etc.....

Not sure what you're about, but

make -j6
gives up to 6 parallel processes (that '6' can be any reasonable number of your choice).

alias make="make -j6"
makes that the default on that terminal, or system wide if you put it in /etc/profile.d.

do_this & do_that
starts the 2 processes simultaneously. The funniest one of these goes back to dial up days when my eager young hackers wanted online and I didn't want to give them root. I would log into a root console, type
wvdial & exit
and the screen would return to a login screen while the modem could still be heard chattering away :-P.