Basic HTML version of Foils prepared 10 Oct 1995

Foil 16 Comments on Parallel Input/Output - I

From Fox Presentation Fall 1995 CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Geoffrey C. Fox
Parallel I/O has technical issues -- how best to optimize access to a file whose contents may be stored on N different disks which can deliver data in parallel and
Semantic issues -- what does printf in C (and PRINT in Fortran) mean?
The meaning of printf/PRINT is both undefined and changing
  • In my old Caltech days, printf on a node of a parallel machine was a modification of UNIX which automatically transferred data from nodes to "host" and produced a single stream
  • In those days, full UNIX did not run on every node of machine
  • We introduced new UNIX I/O modes (singular and multiple) to define meaning of parallel I/O and I thought this was a great idea but it didn't catch on!!

© on Tue Oct 7 1997