Re: Bonded gigabit cards

[Eric Nodwell <nodwell@physics.ubc.ca>]

On Thu, Aug 07, 2003 at 03:42:44PM -0700, Support List wrote:
> wow, this is very interesting for me.  why?  because due to my rather small
> university student budget, i work with somewhat older hardware.  my cluster
> runs off 16 port hubs, and of course, when it gets going, that collision
> light is solid.  and to say the least, that doesn't help things.  so being
> able to split up the bandwidth between hubs would be a huge asset.  (i have
> a lot of old 12 and 16 port 10base hubs lying around)
> 
> now, for a couple questions.  can this be expanded to more than 2 nics?
> could i bond together 3 or 4 nics for 3 or 4 x 10BaseT throughput?  of
> course, this would get a bit expensive in the nics, but a few more pci nics
> is a lot cheaper than 16 or 24 port switches.

Yes, you can go to 3 or 4 nics.  I would definitely benchmark it
though, because I've seen reports where for some reason no speed
increase was gained with 3+.  (I've also seen cases where it was
actually 3 times as fast.)

> also, what packages are required to do this?  or is this a module in the
> kernel that i need to make sure i activate when i recompile the mosix
> enabled kernel?

You need the "bonding" kernel module.  In Debian, you also need the
package ifenslave.  I think that's sufficient.

> lastly, on a slightly different note, can this be applied to simply having a
> single computer having two nics plug into the same network[hub] acting as a
> single nic?

Only if you have a fancy (managed) switch which supports channel
bonding.

>  can the rest of the network handle having their incoming
> traffic coming from 2 different hardware locations, even though the software
> says it's one?

With the above-mentioned fancy switch, it's transparent to the rest of
the network.  Otherwise, no, it won't work.  From previous email:
channel bonded and non-channel bonded don't interoperate.  To get
access to the outside world (without a fancy switch), you need one
computer with 3 nics: 2 channel-bonded to your cluster, 1 normal
connection to the Internet.

Eric