[rescue] Any Minneapolis area listers ?

Charles Shannon Hendrix shannon at widomaker.com
Thu Jan 11 09:33:32 CST 2007

Thu, 11 Jan 2007 @ 08:53 -0600, Lionel Peterson said:

> >From: Jay Monkman <jtm-rescue at smoothsmoothie.com>
> >Date: 2007/01/10 Wed PM 03:59:49 CST
> >To: The Rescue List <rescue at sunhelp.org>
> >Subject: Re: [rescue] Any Minneapolis area listers ?
> >On Wed, Jan 10, 2007 at 09:50:54AM -0500, Ethan O'Toole wrote:
> >> As far as spanning multiple cards, you would probably be better off with 4
> >> 4-port raid cards running software raid against them all or something,
> >> than one 16 port card.
> >
> >That's not necessarily true. 4 drives on one card can completely
> >saturate a 33MHz/32 bit PCI bus. 4 drives @ 50 MB/s = 1.6Gbps. 4 of 
> >those will saturate a 100MHz/64 bit bus.
> Finding a current MB with 4 PCI slots is challenging (NOT impossible,
> but your choices are very limited)...

Part of the reason for that is so many boards have moved to PCIe, which
can at least partially eliminate the need for multiple cards.

The other part is that PCI isn't very good at more than 4 slots, and one
slot at least is usually taken up by motherboard components.

> Also, what is the difference between one 12 port card on a PCI bus vs.
> three 4 port cards on a PCI bus (aside from simple hardware
> redundancy, where you you now have three point s of failure instead of
> one, but hopefully one-third the impact when one of the three fails)?

It depends on the quality of the cards.

A lot of RAID cards have more ports on them than their CPUs can
effectively handle at full speed.

The other issue is multi-path controller routing in case of controller
failure. I've never done that but some people swear by it or at it in
equal measure.

shannon "AT" widomaker.com -- ["All of us get lost in the darkness,
dreamers turn to look at the stars" -- Rush ]

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