[Pw_forum] -D__NEW_PUNCH option

Paolo Giannozzi giannozz at nest.sns.it
Thu Dec 2 15:48:34 CET 2004


On Thursday 02 December 2004 12:17, Sergey Lisenkov wrote:

> I would like to know about the status of -D__NEW_PUNCH option

superseded by input variable "wf_collect", as explained (sort of) 
in the manual (but unfortunately not in the INPUT_PW file):

        Note that each processor writes its own set of temporary
        wavefunction files during the calculation. If wf_collect=.true. (in
        namelist control), the final result is collected into a single file,
        whose format is independent on the number of processors; otherwise,
        one wavefunction file per processor is left on the disk. In the
        latter case, the files are readable only by a job running on the
        same number of processors and pools, and if all files are on a file
        system that is visible to all processors (i.e., you cannot use local
        scratch directories: there is presently no way to ensure that the
        distribution of processes on processors will follow the same pattern
        for different jobs).

> Is it possible to reduce a load of NFS?

write to local scratch disks. Note that you have no control on 
which processor writes the output file if wf_collect=.true., so you 
may have to hunt for your data file a little bit

Paolo

-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
Piazza dei Cavalieri 7      I-56126 Pisa, Italy



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