[gmx-users] tpbconv ... -np option.

[Senthil Kandasamy]

I have been running a simulation for about 10 ns on 4 nodes of a
cluster. I am going to lose access to this cluster soon and need to
continue this run on a different cluster. However, on the second
cluster, scaling over 4 nodes is really bad. I would rather run it on a
single processor or maybe two. To get a continuous trajectory and to run
on a different number of processor, what really are my options?  

Since tpbconv cannot change the np option, i will have to go back to
grompp and recreate a tpr file. However, from the new input gro file,
the information I provide contains only coordinates and velocities. The
Forces are lost, leading to a discontinuous trajectory (am I correct in
stating this?)

grompp -f samemdp.mdp -c f210ns.gro -p sametop.top -np (1 or 2)
newtpr.tpr

I see a -t option for grompp. Does this recreate a continuous
trajectory?

I have about 8 simulations that need to be migrated and it would really
improve my efficiency if I can recompile them for two processors or even
one.

Thanks.

Senthil