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Subject: Re: SCSI, U2W in particular?, and poor performance...
From: Justin Robertson (zululinux.com)
Date: Sat Mar 04 2000 - 21:32:05 CST

Linux Redhat, Linux Debian, Linux Slackware.
All had the same issues... kernel version 2.2.12, 2.2.14, 2.2.14...
The box I was talking about comparing it to was running Linux Debian w/
kernel 2.2.14.

Justin Robertson
<zululinux.com>

On Sat, 4 Mar 2000, Wietse Venema wrote:

> Um, what SOFTWARE was runing on these boxen? There are
> significant differences in speed and reliability.
>
> Wietse
>
> Justin Robertson:
> >
> > Using fsstone and smtpstone, I've noticed some 'quirks' in performance.
> > For example, on an extremely low end Celeron 400 with 32MB of ram and a
> > cheap 6.4gig IDE HD, I can succesfully create/delete 1024 files using
> > fsstone in about 2 seconds. Using smtp-source I can send 1000 15k messages
> > in 44 seconds, using only 2% of the CPU. Now, this is good, however, when
> > the same tests are attempted on a conciderably higher end box, 800MHz,
> > 768MB of RAM, and 10,000rpm 18.2gig U2W SCSI HDs, the results are... well,
> > far lower then the low end machine. It takes 14 seconds to perform the
> > same fsstone test, and well over 7 minutes to perform the same
> > smtp-source test. Perplexed I attempted a series of CPU and HD tests on
> > the high end machine, and it was performing as would be expected. Is there
> > something about the way that postfix reads/writes data that is 'iffy' in
> > the SCSI drivers at this point? This would make no sense to me... I've
> > check with another individual whom is using a different SCSI controller
> > card, ncr xxx vs. my adaptec a2940u2w, and the results are comprable. What
> > gives? Anybody have an idea? I could just put everything on to a RAM disk,
> > but the point is that a crappy machine shoudln't be smoking the highend
> > box.
> >
> >
> > Justin Robertson
> > <zululinux.com>
> >
> >
> >
> >
> >
> >
>
>