Merge pull request #14329 from marcosvanella/master

FDS Source and User Guide: Switch default SMV parallel write to .FALSE.

Author: marcosvanella

Manuals/FDS_User_Guide/FDS_User_Guide.tex

@@ -9577,7 +9577,7 @@ \chapter{Output}
 \item A list of HVAC output quantities is given in Sec.~\ref{info:hvacoutputquantities}.
 \end{itemize}
 The namelist group \ct{DUMP} contains parameters (Table \ref{tbl:DUMP}) that control the rate at which output files are written, and various other global parameters associated with output files. There can only be one \ct{DUMP} line in the input file.
-By default, FDS outputs all result files to the current working directory. A separate output directory for binary files can be specified by the user by setting \ct{RESULTS_DIR} on the \ct{DUMP} line. A single text file \ct{CHID.smv} is always written with high level information about the case~\cite{Smokeview_Users_Guide}. By default, this file is written in parallel using MPI I/O routines. This feature can be disable setting \ct{SMV_PARALLEL_WRITE=F} in the \ct{DUMP} line, in which case, MPI rank 0 will write the file.
+By default, FDS outputs all result files to the current working directory. A separate output directory for binary files can be specified by the user by setting \ct{RESULTS_DIR} on the \ct{DUMP} line. A single text file \ct{CHID.smv} is always written with high level information about the case~\cite{Smokeview_Users_Guide}. By default, the information is gathered in MPI rank 0 which writes the file. For computations involving parallel file systems and many MPI processes, the file can also be written in parallel using MPI I/O routines setting \ct{SMV_PARALLEL_WRITE=T} in the \ct{DUMP} line.
 
 
 \section{Controlling the Frequency of Output}

Source/cons.f90

@@ -196,7 +196,7 @@ MODULE GLOBAL_CONSTANTS
 LOGICAL :: SETUP_ONLY=.FALSE.               !< Indicates that the calculation should be stopped before time-stepping
 LOGICAL :: CHECK_MESH_ALIGNMENT=.FALSE.     !< Indicates that the user wants to check the mesh alignment and then stop
 LOGICAL :: SMOKE3D=.TRUE.                   !< Indicates that the 3D smoke and fire output is desired
-LOGICAL :: SMV_PARALLEL_WRITE=.TRUE.        !< If true, the CHID.smv file is written in parallel using MPI-IO.
+LOGICAL :: SMV_PARALLEL_WRITE=.FALSE.       !< If true, the CHID.smv file is written in parallel using MPI-IO.
 LOGICAL :: STATUS_FILES=.FALSE.             !< Produce an output file CHID.notready which is deleted if the simulation completes
 LOGICAL :: LOCK_TIME_STEP=.FALSE.           !< Do not allow time step to change for diagnostic purposes
 LOGICAL :: RESTRICT_TIME_STEP=.TRUE.        !< Do not let the time step increase above its intial value