<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> <html> <head> <title>Environment Variables and Configuration Parameters</title> <!-- #BeginLibraryItem "/ed_libs/styles_UG.lbi" --> <!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Copyright by the Board of Trustees of the University of Illinois. * * All rights reserved. * * * * This file is part of HDF5. The full HDF5 copyright notice, including * * terms governing use, modification, and redistribution, is contained in * * the files COPYING and Copyright.html. COPYING can be found at the root * * of the source code distribution tree; Copyright.html can be found at the * * root level of an installed copy of the electronic HDF5 document set and * * is linked from the top-level documents page. It can also be found at * * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html. If you do not have * * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * --> <link href="ed_styles/UGelect.css" rel="stylesheet" type="text/css"> <!-- #EndLibraryItem --></head> <body bgcolor="#FFFFFF"> <!-- #BeginLibraryItem "/ed_libs/NavBar_UG.lbi" --><hr> <center> <table border=0 width=98%> <tr><td valign=top align=left> <a href="index.html">HDF5 documents and links</a> <br> <a href="H5.intro.html">Introduction to HDF5</a> <br> <a href="RM_H5Front.html">HDF5 Reference Manual</a> <br> <a href="http://hdf.ncsa.uiuc.edu/HDF5/doc/UG/index.html">HDF5 User's Guide for Release 1.6</a> <br> <!-- <a href="Glossary.html">Glossary</a><br> --> </td> <td valign=top align=right> And in this document, the <a href="H5.user.html"><strong>HDF5 User's Guide from Release 1.4.5:</strong></a> <br> <a href="Files.html">Files</a> <a href="Datasets.html">Datasets</a> <a href="Datatypes.html">Datatypes</a> <a href="Dataspaces.html">Dataspaces</a> <a href="Groups.html">Groups</a> <br> <a href="References.html">References</a> <a href="Attributes.html">Attributes</a> <a href="Properties.html">Property Lists</a> <a href="Errors.html">Error Handling</a> <br> <a href="Filters.html">Filters</a> <a href="Caching.html">Caching</a> <a href="Chunking.html">Chunking</a> <a href="MountingFiles.html">Mounting Files</a> <br> <a href="Performance.html">Performance</a> <a href="Debugging.html">Debugging</a> <a href="Environment.html">Environment</a> <a href="ddl.html">DDL</a> </td></tr> </table> </center> <hr> <!-- #EndLibraryItem --><h1>HDF5 Library Environment Variables and Configuration Parameters</h1> <h2>1. Environment Variables</h2> The HDF5 library uses UNIX environment variables to control or adjust certain library features at runtime. The variables and their defined effects are as follows: <dir> <dl> <dt><tt>HDF5_DEBUG</tt> <dd>Defines a list of debugging switches documented in the <a href="Debugging.html">Debugging</a> section of the <cite>HDF5 User's Guide</cite>. <dt><tt>HDF5_NOCLEANUP</tt> <dd>When set to a non-empty value, the programs in the test directory do not remove temporary HDF5 data files. The default is for each test to remove the files before exit. <dt><tt>HDF5_MPI_OPT_TYPES</tt> (for parallel beta version only) <dd>When set to <code>1</code>, PHDF5 will use the MPI optimized code to perform parallel read/write accesses to datasets. Currently, this optimization fails when accessing extendable datasets. The default is not to use the optimized code. <dt><tt>HDF5_MPI_1_METAWRITE</tt> (for parallel beta version only) <dd>When set to <code>1</code>, PHDF5 will write the metadata via process 0 of each opened parallel HDF5 file. This should improve I/O throughput. The default is not to use this optimization. </dl> </dir> <h2>2. Configuration Parameters</h2> The HDF5 configuration script accepts a list of parameters to control configuration features when creating the Makefiles for the library. The command <br> <code> configure --help </code> <br> will display the current list of parameters and their effects. <br><br> <!-- #BeginLibraryItem "/ed_libs/NavBar_UG.lbi" --><hr> <center> <table border=0 width=98%> <tr><td valign=top align=left> <a href="index.html">HDF5 documents and links</a> <br> <a href="H5.intro.html">Introduction to HDF5</a> <br> <a href="RM_H5Front.html">HDF5 Reference Manual</a> <br> <a href="http://hdf.ncsa.uiuc.edu/HDF5/doc/UG/index.html">HDF5 User's Guide for Release 1.6</a> <br> <!-- <a href="Glossary.html">Glossary</a><br> --> </td> <td valign=top align=right> And in this document, the <a href="H5.user.html"><strong>HDF5 User's Guide from Release 1.4.5:</strong></a> <br> <a href="Files.html">Files</a> <a href="Datasets.html">Datasets</a> <a href="Datatypes.html">Datatypes</a> <a href="Dataspaces.html">Dataspaces</a> <a href="Groups.html">Groups</a> <br> <a href="References.html">References</a> <a href="Attributes.html">Attributes</a> <a href="Properties.html">Property Lists</a> <a href="Errors.html">Error Handling</a> <br> <a href="Filters.html">Filters</a> <a href="Caching.html">Caching</a> <a href="Chunking.html">Chunking</a> <a href="MountingFiles.html">Mounting Files</a> <br> <a href="Performance.html">Performance</a> <a href="Debugging.html">Debugging</a> <a href="Environment.html">Environment</a> <a href="ddl.html">DDL</a> </td></tr> </table> </center> <hr> <!-- #EndLibraryItem --><!-- #BeginLibraryItem "/ed_libs/Footer.lbi" --><address> <a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a> <br> Describes HDF5 Release 1.4.5, February 2003 </address><!-- #EndLibraryItem --> Last modified: 13 December 1999 </body> </html>