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Re: Disk performance for large partitions?
- To: misc_(_at_)_openbsd_(_dot_)_org
- Subject: Re: Disk performance for large partitions?
- From: "David Corlette" <corlette_(_at_)_huarp_(_dot_)_harvard_(_dot_)_edu>
- Date: Wed, 15 May 2002 17:10:16 -0400
- Organization: Harvard University
> Yes, there are quality concerns; the cheaper boxes are going to
> fail more often and need more attention. But they're not five
> times more likely to fail, even though they cost a fifth as
> much. I'd argue that, even if they're twice as likely to fail,
> they still make economic sense at these prices. My experiences
> are that they're nowhere near twice as likely to fail. Less
> reliable? Sure, but they're not going to fail twice as fast. They
> might--*might*--perform a couple percent slower, but, in most
> practical situations, they'll still saturate any network link.
In principle, what you're saying makes a certain amount of sense. My
experience, however, is that the cheapo boxes don't always work as
well as you're claiming. You say, when the first one fails, you just
drop in the other one. But what if the second one has the same flaw?
And the third?
I had a situation like this with a 2U rackmount from a cheapo
rackmount vendor. Since full-height PCI cards didn't fit in the box
in the normal way, they used a PCI riser card to situate the cards
sideways. The PCI riser card went in one of the existing PCI slots,
and there were little daughter cards that went in the other PCI
This was all well and good, but when I put in an Adaptec SCSI card in
that configuration, things started to fail strangely. I eventually
tracked it down to a subtle timing issue relating to the different
path length in the riser card. In this case, there was a partial
workaround, and the system has worked relatively well since then
(although I lost a PCI slot as a result). But let's say there wasn't
a workaround, or the sysman didn't have the tools to debug the
problem. So they go and swap out the hardware with a complete
replacement and lo, it has exactly the same fault!
Compare this with a vendor like Dell or Compaq, who, AFAICT, goes to
all sorts of trouble to make sure that the physical design of their
cases et al are fully up to spec. I very much doubt you'll have the
same sort of systematic trouble with such a system.
My point being, if you go out and buy three junk computers for $1000,
you still have $1000 worth of junk. Whereas if you go and buy a
properly designed system for $1000, you have a functional system.
Realize that I'm playing devil's advocate here; if you were to see my
lab, you'd see that I'm running a lot of junk! But I think that the
converse point to your argument has to be made and understood.
My 2c, sorry for the OT posting...
David Corlette mailto:corlette_(_at_)_huarp_(_dot_)_harvard_(_dot_)_edu
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