[svn-r5657] Updated.

release_docs/INSTALL_parallel

@@ -202,3 +202,13 @@ will print informational essages stating the failure but will not exit
 with non-zero code.  Failure to support file size greater than 2GB is
 not a fatal error for HDF5 becuase HDF5 can use other file-drivers such
 as families of files to by pass the file size limit.
+
+By default, the parallel tests use /tmp/$LOGIN as the test directory.
+This can be override by the environment variable $HDF5_PARAPREFIX.
+For example, if the tests should use directory /PFS/user/me, do
+    HDF5_PARAPREFIX=/PFS/user/me
+    export HDF5_PARAPREFIX
+    make check
+
+(In some batch job system, you many need to hardset HDF5_PARAPREFIX in
+the shell initial files like .profile, .cshrc, etc.)