hdf5/doc/html/Environment.html
Quincey Koziol 138bc92ebd [svn-r8126] Purpose:
Bug fix/optimization

Description:
    Address slowdown in MPI-I/O file metadata operations that was introduced
mid-stream.  We now _require_ a POSIX compliant parallel file system for the
MPI-I/O file driver (as well as for the MPI-POSIX file driver).
    Also optimized file open operation when the file is being created by
reducing the number of collective & syncronizing calls.
    Additionally, refactor the MPI routines into a common place, eliminating
duplicated code.

Platforms tested:
    FreeBSD 4.9 (sleipnir) w/parallel
    h5committest
2004-01-30 20:38:44 -05:00

167 lines
6.7 KiB
HTML

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<title>Environment Variables and Configuration Parameters</title>
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<a href="index.html">HDF5 documents and links</a>&nbsp;<br>
<a href="H5.intro.html">Introduction to HDF5</a>&nbsp;<br>
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;<br>
<a href="http://hdf.ncsa.uiuc.edu/HDF5/doc/UG/index.html">HDF5 User's Guide for Release 1.6</a>&nbsp;<br>
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<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_DISABLE_VERSION_CHECK</tt>
<dd>When set to <code>1</code>, HDF5 will not abort when the version
of the HDF5 headers doesn't match the version of the HDF5 library.
<dt><tt>HDF5_MPI_OPT_TYPES</tt>
&nbsp;&nbsp;(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.
</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>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;configure --help </code>
<br>
will display the current list of parameters and their effects.
<br><br>
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<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a>
<br>
Describes HDF5 Release 1.4.5, February 2003
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Last modified: 13 December 1999
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