Name: H5Pset_dxpl_mpio_chunk_opt
Signature:
herr_t H5Pset_dxpl_mpio_chunk_opt (hid_t dxpl_id, H5FD_mpio_chunk_opt_t opt_mode)
Purpose:
Sets a flag specifying linked-chunk I/O or multi-chunk I/O.
Description:
H5Pset_dxpl_mpio_chunk_opt specifies whether I/O is to be performed as linked-chunk I/O or as multi-chunk I/O. This function overrides the HDF5 Library's internal algorithm for determining which mechanism to use.

When an application uses collective I/O with chunked storage, the HDF5 Library normally uses an internal algorithm to determine whether that I/O activity should be conducted as one linked-chunk I/O or as multi-chunk I/O. H5Pset_dxpl_mpio_chunk_opt is provided so that an application can override the library's alogorithm in circumstances where the library might lack the information needed to make an optimal desision.

H5Pset_dxpl_mpio_chunk_opt works by setting one of the following flags in the parameter opt_mode:

This function works by setting a corresponding property in the dataset transfer property list dxpl_id.

The library perform I/O in the specified manner unless it determines that the low-level MPI IO package does not support the requested behavior; in such cases, the HDF5 Library will internally use independent I/O.

Use of this function is optional.

Parameters:
Returns:
Returns a non-negative value if successful. Otherwise returns a negative value.