[Pw_forum] PHONON errors varies when i use 6 or 2 cpu?

[Xunlei Ding]

Dear xu,
Yes, you are right because ph.x need to read wfc files of scf 
calculation. So the number of cpu should be the same.
Maybe you can try wf_collect=.true. in scf calculation if you want to 
change the cpu number.

And I suggest you to do some small tests on these questions.

Best wishes,
Ding

xu yuehua wrote:

> Dear Ding:
> I think  about your idea , if your idea is correct ,that says:if i use 
> 6 cpu to do scf ,then i must use the same number of cpu to continue 
> tophonon calculation .is it right for  me to comprehend your idea ?
> need your help thanks a lot
>
>  
> 2007/6/8, Xunlei Ding <ding at sissa.it <mailto:ding at sissa.it>>:
>
>     Dear Xu,
>     I think,
>     error for 6 cpu calculation is just because one of the six nodes
>     is down,
>     and error for 4 cpu calculation is because you change 6 cpu to 4 cpu.
>     So my suggestion is, doing the ph calculation with 6 cpu again.
>
>     Hope it will works.
>
>     Yours,
>     ding
>
>
>
>     xu yuehua wrote:
>
>     > hi everyone?
>     > today i met a problem when i compute phonon :first i do scf using 6
>     > cpu ,then i also use 6 cpu to do phono at G,BUT a problem came
>     out in
>     > out.file :
>     >
>     >
>     >
>     >  Proc/  planes cols    G   planes cols    G    columns  G
>     >  Pool       (dense grid)      (smooth grid)   (wavefct grid)
>     >   1      5   3284  53988    4   2408  34052  719   5577
>     >   2      4   3283  53987    4   2407  34051  719   5577
>     >   3      4   3283  53987    4   2407  34049  719   5577
>     >   4      4   3283  53987    4   2407  34051  719   5577
>     >   5      4   3283  53987    4   2407  34049  719   5577
>     >   6      4   3283  53987    4   2407  34051  720   5576
>     >   0     25  19699 323923   24  14443 204303 4315  33461
>     >
>     >
>     >      nbndx  =    20  nbnd   =    20  natomwfc =    30  npwx  
>     =    4282
>     >      nelec  =  40.00  nkb   =    50  ngl    =   10269
>     > p0_9381:  p4_error: net_recv read:  probable EOF on socket: 1
>     > Killed by signal 2.^M
>     > forrtl: error (69): process interrupted (SIGINT)
>     > Killed by signal 2.^M
>     > Killed by signal 2.^M
>     > Killed by signal 2.^M
>     > Killed by signal 2.^M
>     > p0_9381: (12.363281) net_send: could not write to fd=4, errno = 32
>     > Fri Jun  8 09:41:35 CST 2007
>     >
>     > because i do not know the reason .and then i try to use 4 cpu to
>     > compute phono  ,this time the error is like this :
>     >
>     >
>     >
>     >
>     > Representation    44      1 modes - To be done
>     >
>     >      Representation    45      1 modes - To be done
>     >  IOS = 36
>     >
>     >  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>     >      from davcio : error #        20
>     >      i/o error in davcio
>     >  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>     >
>     >
>     >      stopping ...
>     >
>     >  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
>     >      from davcio : error #        20
>     >      i/o error in davcio
>     >  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>     >
>     >
>     >      stopping ...
>     > [0] MPI Abort by user Aborting program !
>     > [0] Aborting program!
>     > p0_11006:  p4_error: : 0
>     > Killed by signal 2.^M
>     > forrtl: error (69): process interrupted (SIGINT)
>     > p0_11006: (18.296875 ) net_send: could not write to fd=4, errno
>     = 32
>     > Fri Jun  8 09:57:22 CST 2007
>     >
>     > above two case ,the same input:
>     > phonons of fiveringwater at Gamma
>     >  &inputph
>     >   tr2_ph=1.0d-14,
>     >   prefix='fxx_specify_ibra_500_12+force',
>     >   epsil=.true.,
>     >   amass(1)=1.0,
>     >   amass(2)=15.999,
>     >   outdir='/raid/xx/pwscf/tmp/',
>     >   fildyn='fxx.dynG',
>     >  /
>     > 0.0 0.0 0.0
>     >
>     >
>     >
>     >
>     >
>     > so my question is  why different number of cpu can change the
>     error ?
>     > befor a few days ago ,i use 2 cpu to do relax ,scf and phonon about
>     > another case ,there was well ,but now .....?
>     > i need your  help .thanks
>     >
>     > --
>     > Xu Yuehua
>     > physics Department of Nanjing university
>     > China
>
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>
>
>
> -- 
> Xu Yuehua
> physics Department of Nanjing university
> China