[CentOS] Server hangs on CentOS 5.5

>According to the man page, it apparently needs a kernel driver
>named OpenIMPI, which it claims is installed in standard
>distributions.  I don't find it on my system.


lm_sensors is another, and I think installs ready to use from the repos.

Failing that, you should reboot and look in the motherboard's bios/cmos. It
should display all that good stuff: fan speeds, voltage levels, temps.