Question: Task Farm and Private Networks.

[Andreas Boklund]

> I currently have a small cluster in which the slave nodes are on a private
> network. It is used primarily as a task farm and not as a true parallel
> machine. Only the master node sees our other systems  (which are on their
> own switch). This casues problems with certain remote job submissions via
> some commercial packages since they write both local temp files and scratch
> temp files.
> 
> Question: What is the drawback to giving each slave it's own true IP address
> and allowing them to NFS mount the same file systems as the master node?
> 
> Thanks

Hi,
I have a system where the nodes are on a private network and they mount 
the same NFS shares as all other UNIX computers on our network. The reason
that we do this is that the users sometimes want stuff from their /home/
dirs. 

I didnt use true IP-adresses because our IP-adressspace is limited. What i
did was just to place a NAT on the master node that translates the node
adresses to the master nodes adress. Actually this was one of the reasons
that i used the 2.3pre release kernels in this cluster, i wanted to use
IP-tables. It is very easy to set it up this way. And if you dont want the
traffic to go through the master node you can always add communications
node that will only handle traffic to and from your backbone, a P 200
64MB ram should be able to forward enough traffic for two FastEthernet
NICs, and i bet you can find one lying around somwehere.


Best Regards
//Andreas
F-Lab Research



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