[rescue] Overkill on an SS2

[Joshua D Boyd]

On Mon, Jun 17, 2002 at 01:43:04PM -0700, James Lockwood wrote:
> On Mon, 17 Jun 2002, Joshua D Boyd wrote:
> 
> > We'll see what I can come up with.  The space will come from some not
> > yet determined number of seagate elite 23s that will be just striped.
> > I've thought of, but haven't decided) of throughing in a FastSCSI2
> > card with intergrated ethernet.  Then I could put the fast disks on a
> 
> Rather than throw the money at a FSBE/S or similar, I highly recommend
> going to a divorced IO/memory architecture like the SS5.  Remember, in the
> SS2 _everything_ goes through the Sbus and it can become quite a
> bottleneck.  Thou'lt get better perf in most cases from a SS5/70 with a
> single fast SCSI channel than a SS2 with both a slow and a fast channel.

Well, in theory I'm getting a few such machines sometime.  In the mean
time, I'm trying to make do with what is in my possesion, and the
chances are I'm going to want such cards in newer systems when they
arrive anyway.

But, I was aware of that split, and hence am saving the Classic (which
is also a 4m) for when the raid array arrives (along with a fast card
and a faste card).  But, I need both fast and reliable disk space, and
also a lot of disk space that doesn't need to be too fast or reliable
(meaning while I want it to last, I won't have a heart attack if it
does fail sometime).
 
> Going to multiple spindles will help considerably with latency, as the
> 10mbps ethernet connection is clearly the bottleneck with regards to
> bandwidth.  Try that first.  SCSI transaction latency is not big enough to
> bite you even with everything on one chain, the onboard SS2 SCSI bus can
> saturate 10mbps ethernet fourfold even with overhead factored in.

Hmm.  Well, since I still want the second ethernet, the second scsi
will be in the machine anyway, so might as well use it.

-- 
Joshua D. Boyd