[Wien] k-point parallel job in distributed file system

[Ravindran Ponniah]

Hello,

 	We are trying to do k-point parallel wien2k job in a linux cluster 
which has distributed file system. Though we are able to do k-point 
parallel calculation, we have a problem in assigning a 
common work space ($SCRATCH) to read/write all input/output files. This 
means that, for example, if we do a 10 kpoint calculation in 10 nodes, all 
the 10 nodes should communicate to the common working area through ssh to 
read/write files. This slows down the performance and also the network. 
So far we have done k-point parallel calculations in supercomputers with 
shared memory and hence we never had such a problem.  Is it 
possible to do k-point parallel calculations in distributed file system 
without any common working area?

I have received the following from the system expert here.

###
Hmm, I've been looking through the jungle of scipts which constitutes 
wien2k, and it is clear to me that
this way of paralellizing isn't meant for distributed filesystems (local 
disks on nodes). Unless the
wien2k people have a solution, I don't think we will get around this 
without some major reprogramming. At
least it seems so to me, but I must admit that I don't have the complete 
overview of todo tasks.

Also a quick google of the proble, did not provide a solution.
This is very efficient for SMP types of machines, but is a bit 
ad-hoc for cluster type computers.
On the bright side, it doesn't seem taht the program does a lot of disk 
read/write in the long run. Only 10-20 min bursts of 10 megs/sek.
####

Looking forward your responses to do the computation more efficently.

Best regards
Ravi