[K12OSN] Just about ready to make a purchase

[Robert Arkiletian]

On 5/8/07, Jim Kronebusch <jim at winonacotter.org> wrote:
> > Having said that, I've never seen performance numbers for dual-dual
> > adapters in a quad-bond configuration on a PCIx or PCIe bus.  It is
> > certainly possible that either configuration would work.  Which of
> > them is more scalable, and probably cheaper?  Almost definitely the
> > subnet-per-NIC approach.
> >
> > -dhbarr.
>
> :-) I haven't seen those types of performance numbers either.  I am set up that I can
> easily incorporate placing individual NIC's on separate VLAN's.  I believe I don't have
> room enough in the server to put 4 separate NICs.  However I could still use 2 dual nics
> and put each of them on a separate VLAN, but then if the PCI bus is the limitation and
> not the teaming, I should essentially end up with the same problem.

You wrote that you had 2 dual port Intel 1000MT NICS. I think 1 pair
should be built into the MB. They are NOT connected to the PCI bus.
They have to be connected to the PCI-X bus or nobody would buy it. The
PCI bus can barely support 1 GigE bandwidth. PCI-X or PCIe have much
more bandwidth. PCIe (PCI Express) is not as popular in enterprise
grade stuff yet cause it's not as mature as PCI-X. Your server must
have available PCI-X slots.

>
> Unfortunately I don't have a good way to test all methods before implementation.
> Luckily if the network does end up being a bottleneck, re-configuration of the network
> should be fairly trivial.
>
> Another thought about NICs, 2 of the GB NIC's are actually onboard and the other 2 are a
> PCIx dual port card.  So only 2 GB ports would be on the PCIx bus, would that help
> alleviate the PCIx bottleneck?

I should have read your entire post.  Both your dual GB NICS are on
the PCI-X bus.

>
> Also a note the comment in an earlier post about splitting the mirrors onto separate
> controller interfaces, it looks like for an extra $300 I can split the backplane into
> 2x5 hotplug backplanes.  I will contact Dell to see if this would allow me to spread my
> RAID array across both on separate interfaces.
>

I have received advice (maybe from Les) that if one scsi drive dies it
can *potentially* mess up the bus on that channel. That's why I like
to use dual interface scsi controllers and build the mirror on
separate channels. Seems logical enough.

Seems kind of pricey for an extra scsi cable though. Most likely you
can't just buy another scsi cable as Dell has to integrate it into the
backplane.

-- 
Robert Arkiletian
Eric Hamber Secondary, Vancouver, Canada
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