[SGVLUG] Distributed filesystems

Michael Proctor-Smith mproctor at surfcity.net
Thu Jun 23 14:29:04 PDT 2005



On Thu, 2005-06-23 at 14:09, Emerson, Tom wrote:
> five pages in on pricewatches search results for GIGABIT ETHERNET gets
> you to actual networking cards (vs. mainly cables up to that point) at
> a price point of $15 or less.  A couple of pages later gets a
> "complete kit" at $40 [though only two NICs and I presume a
> "crossover" cable -- no switch or hub] and the lowest priced gigabit
> SWITCH is on the next page at $54 (netgear, no less!) so price
> shouldn't be a barrier to "upgrading" [though admittedly you never
> said it was...]

My 8 port Gigabit switch(I don't think there is such a thing as a
gigabit hub) cost me less then fifty bucks on ebay. My gigabit cards
cost less that 10 bucks on ebay.
> 
> OTOH, I imagine that those bargain-basement cards will actually be
> WORSE for your environment (driver issues notwithstanding) as I
> suspect these will be (effectively) "winmodem" style NICS, i.e., they
> make heavy use of your own CPU to do the work that you bought them for
> in the first place [think of it this way: if you were do hook up the
> interrupt line to the clock line, you'd overclock your CPU... ;) ]

My experance has been that I achieve disk speed over nfs, over gigabit
ethernet. With my bargain-basement cards(realtech based cards).
My cards were slow as hell with 2.4 kernel drivers but when I upgraded
to a based 2.6.X kernel.

> final thought: the folks that produce Cinelarra (a.k.a.
> "broadcast2000") also maintain something they call the firehose (or
> something like that...) which is a method of connecting multiple
> USB-2.0 and/or FIREWIRE ports between two computers to get an
> outrageous "combined" network speed -- i.e., 5 usb2.0 ports connected
> between machines should get you 2gigabits or more (isn't usb2 rated at
> 400mbs, or is that firewire?)
> 
USB 2.0 is 480mbs peak bust speed. Firewire 1394b is 400mbs sustained
transfer, 1394a called firewire 800 is 800mbs sustained transfer.
USB and firewire are the old ide(usb) vs. scsi(firewire) in that one is
rated for peak and the other is rated for sustained and that one is now
a requirement and the other is only used by people who know what they
need.



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