[Beowulf] Rocks Cluster and 2 Ethernet networks

[Reuti]

Hi Timo,

> Thanks for your help.  I have not installed Rocks just yet.  Can you
> explain to me what the ch_p4 device of MPI_CH is?  Nochmals, vielen Dank!

MPI is a standard of a protocol for writing parallel programs. MPICH is one 
implementation of this standard (there are others, also commercial ones). 
Inside MPICH you have different "devices" for communication between the nodes 
to chose from, which will best fit to your computer system and network. The 
ch_p4 device is one, which will use the p4 communication standard. This will 
use rsh/ssh to start the tasks on the nodes. Other devices will need a special 
daemon running on each node. All the programs we use, use the ch_p4 device.

Cheers - Reuti