[Beowulf] Re: RRDtools graphs of temp from IPMI

[Dave Love]

Prentice Bisbal <prentice at ias.edu> writes:

> The advantage of using IPMI is that it is hardware based, so there
> shouldn't be any OS noise to slow down the MPI calculations.

Yes iff you do it out-of-band, which is probably less convenient, and is
significantly slower on our systems, at least.  Actually, is it clear
that interacting with the firmware generally won't cause any jitter?  I
could imagine it might.

Our vendor installed a daemon doing in-band IPMI sensor probes which I
didn't initially know about, since it wasn't sending the ganglia metrics
correctly anyhow.  I don't know whether that means they disagree with
the effect on MPI performance or what.