[gmx-users] md continuation

[Kashif]

I have already run my 20 ns md simulation of my protein. The log file is
showing completion of my 20 ns data. I have also done analysis by using
trjconv command and g_rms.
Now I want to increase my simulation at least for 20 ns more and make my
data of protein simulation for 40 ns. Kindly help for continuation of my
simulation. I have used this command but it did not help and shows error.
command:   mdrun -deffnm md_0_1 -cpi md_0_1.cpt -append

error:
NOTE: 23 % of the run time was spent communicating energies,
      you might want to use the -gcom option of mdrun

                     Core t (s)    Wall t (s)        (%)
       Time:       25.000        2.843         879.2
                      (ns/day)        (hour/ns)
Performance:        0.061      394.912
Finished mdrun on node 0 Sat Apr 29 11:46:36 2017

regards
kashif