[Pw_forum] Question of a system administrator about pw.x usage

[Paolo Giannozzi]

On Sep 21, 2012, at 19:10 , Silas Silva wrote:

> After hours of execution, the system load increases absurdly.
> We can see it is I/O stuff, but we could not discover why it
> happens later in the execution of the program nor how to fix it.

because at the end of the execution the code, if so instructed
(input variable "wf_collect"), collects big arrays that are distributed
across all processors to a single processor, that in turn writes
them to disk. This is needed only if you want to use those data
for further processing.

> 3. Is there any flag or configuration we can pass to pw.x to see  
> what it
>    is doing?  Any debug flag?

no. There is nothing to debug anyway: it is well known that one should
not read or even worse write big files via NFS

> 4. Variables you place in input file are documented anywhere?

of course they are: in PW/Doc/INPUT_PW.* and in the
www.quantum-espresso.org web site

P.
---
Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222