[mpich-discuss] read the same file on all processes

[Rajeev Thakur]

How big is the file? What kind of file system is it on?

Rajeev 

> -----Original Message-----
> From: owner-mpich-discuss at mcs.anl.gov 
> [mailto:owner-mpich-discuss at mcs.anl.gov] On Behalf Of 
> Kamaraju Kusumanchi
> Sent: Tuesday, October 21, 2008 8:27 PM
> To: mpich-discuss at mcs.anl.gov
> Subject: [mpich-discuss] read the same file on all processes
> 
> Hi all,
> 
>     I have a file which needs to be read on all the processes 
> of an MPI job. If I read the same file simultaneously on all 
> the processes, will it cause any problems?
> 
>     I can think of two other options such as
> 
> - make multiple copies of the same file and read a separate 
> file on different processes
> - read the file on rank 0 process, then use MPI_Bcast and 
> transfer the contents across the remaining processes.
> 
>    Which approach should be preferred? I am thinking this 
> must be something encountered by others. So, if there is a 
> book/web page which explains these kind of things, a pointer 
> to them would be most appreciated.
> 
> regards
> raju
> 
>