On Sun, 2008-06-08 at 07:33 -0400, Mag Gam wrote:Mag,
> Again, I appreciate the responses.
>
> Damon:
>
> I am dealing with HW RAID. I looked for the "geometry" for my
> controller, but could not find it.
>
> http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual&lang=en&cc=us&docIndexId=64179&taskId=101&prodTypeId=329290&prodSeriesId=1157686
>
> I am very curious about the geometry too...
>
> I don't know enough to pick and choose the optimal setting. Since I
> am working in the academic field, I would like to really understand
> this "geometry setting". Can someone please elaborate on this topic?
>
> TIA
It looks like your controller does not let you set very much manually:
page 13 shows you can set the Stripe Size. At this point, jump in and
play. But again, I don't think it will amount to a hill of beans. The
controller "masks" all reads and writes to the physical drives and the
OS is ignorant of the underlining details. IF you needed to set it up a
certain way, you would KNOW it. And even so, it looks like the only
things you can adjust with this controller is the stripe size. In
almost all cases the "optimal" setting is the default of the controller
when you use it's setup "wizard" thingy, what ever it may be called.
All other deviations are for very specific instructions in some manual
for some application (or you spend much time bench testing to arrive at
what works best for you with that given hardware). Some advice: unless
you are being graded in some way on the maximum through put of this
server: Jump in, install it and be done.
We (IT) don't know the "optimum" settings of such things. We play with
it per some set of (specific) directions or we have a test box we can
bench test to meet some objective with. This concept is a moving,
slippery thing. It all depends on your network throughput, latency, cpu
load, bus load, I/O of every other component, I/O of the controller,
it's (the controller) memory, physical hd read/write speed and probably
a few more I can't think of right now.
Kill this beast, install the os using defaults for the HDs, see if you
can serve up the files at a rate that works for you, if not, look it
over again.
BTW, on the next model server you get, everything you learn here will
not be valid unless it is the exact same set of hardware. That is why I
would not fret over this, there is no "great maxim" to be learned except
"can I set up THIS box to work at the rate I need?" Sometimes the
answer is no, but that falls onto the procurement end of the deal.
A DBA will spend much time telling a sys admin what strip to put onto a
RAID (using a hardware controller), but that is from the application mfg
having benched tested a specific model of server with very specific
hardware to arrive at the best throughput possible with a given hardware
load out. This is not your situation. The only answer is to test.
Anyway, that is my 2C worth.