[Benchmarking] Some thoughts about a disk bound test

[Adrian Custer]

Hey Andrea, All,

On Mon, 2010-09-13 at 09:15 +0200, Andrea Aime wrote:
> Hi,
> I was thinking about the possibility of making a disk bound
> test next year.

During some wonderful hours in the squares and cafés of Barcelona this
weekend, I got to digest the exercise some more and plan for the future.
After many hours of thought, my analysis has certainly evolved.


> The current server setup is quite un-balanced on that point of
> view: we have 8 cpu's (which allows for a good cpu bound testing)
> but the disk subsystem is low performance, single disk with rather
> low throughput and high seek times (mind, I'm not complaining,
> I'm very grateful we have such hardware to start with, just making
> an honest assessment of what I think would be necessary to perform
> a disk bound test).
> 
> If next year we're going to make a I/O bound testing we should make
> sure we have a better disk subsystem, which also implies we should
> look for funding to get one.

Why? 

Once again, it all depends what the test is trying to *do*. If one wants
'realistic' numbers, we might have to buff up this weak link. However,
if we are trying either to discriminate between servers or to find
weaknesses in our own server, then the slower the disk the better --- it
highlights any issues there might be.


> 
> Opinions, suggestions?
> 

I believe we have a *lot* of work to do defining our own aims and goals
before we launch into hardware purchases or sponsorship requests. Let us
work on defining our goals, develop the tests we want to perform, and
prepare the groundwork for any future tests before worrying about the
hardware.

I hope to issue a longish document with my analysis and proposals
sometime in the near future. For now however, I need to catch back up
and prepare the OGC meeting in Toulouse next week.

ciao,

--adrian