[Beowulf] RAID for home beowulf

[Greg Kurtzer]

Hi Greg,

On Mon, Oct 12, 2009 at 4:55 PM, Greg Lindahl <lindahl at pbm.com> wrote:
> On Mon, Oct 12, 2009 at 11:50:10AM -0700, Greg Kurtzer wrote:
>
>> The underlying components that make up a distribution are in-fact an
>> important component to an HPC system in its entirety. There are many
>> reasons for this, but I will focus on just a few that I hope don't
>> strike too much of a religious chord with people while at the same
>> time letting me rant a bit. ;-)
>
> Well, allow me to point out the cow turd you may have stepped in ;-)

Yes. Well aware of the mine field of cow pies all around this area
which was why my response was somewhat carefully constructed instead
of spoken frankly. haha

>
>> 1) HPC people are quite familiar with building their scientific apps
>> with optimized compilers and libraries. If an application is linking
>> against any OS libraries (yes, including the C library) it would
>> probably make sense to make sure those have been compiled with an
>> optimal build environment. Most distributions do not do this,
>
> If the library isn't significantly cpu intensive, then you're better
> off sticking to the best-tested option for your compiler. For gcc,
> that's -O2. Does gcc even bootstrap at -O3 on your favorite platform?
> And pass all the test suites? It's not worth risk unless there's a
> significant performance gain.

Yes, I think we are in total agreement just saying it differently.

Generally there is the core library stack and the rest... The core
stack should NOT be rebuilt by the end users especially with
non-standard compilers and/or optimizations as that will make for a
very difficult to support system. This should be done by the
distribution maintainers themselves such that it is maintainable,
tested and optimized for the target platform.

Some binary based distributions spend much more time on the
tool-chains they use to build the OS then others and this can have a
*noticeable* performance impact.

> Bah, humbug, Gentoo, pthui.

While Gentoo may have some possible,... or potential,... or advertised
performance benefits I personally do not run it on the systems that I
architect because of the inconsistencies with different builds and
installs (I prefer to use identical packages/binaries from one system
to another via RPM guarantying consistency).

Regards,
Greg

-- 
Greg M. Kurtzer
Chief Technology Officer
HPC Systems Architect
Infiscale, Inc. - http://www.infiscale.com