Styjun

I have 14,430 HDF5 files. Each one of these HDF5 files contains a dataset of datatype float of size = 49152 x 21 x 1. I am a trying to create a VDS dataset of size = 49152 x 21 x 14430 mapping each dataset in all the 14,430 files. The code runs fine without errors and I can see that it creates a VDS of size 49152 x 21 x 14430 and writes it to a HDF5 file. However, if I open (or) do a h5dump of the VDS, I see that the VDS has right data until 49152 x 21 x 1024 and rest of the values in the VDS are zeros. It looks like only the first 1024 files are mapped and rest have not been mapped. But if I do “h5dump -p” on the hdf5 file containing the VDS, it shows that all the 14,430 files are virtually mapped. Is there any limit on the memory (or) number of files that can be mapped that I am not aware of? Am I missing something?. I am attaching the code below for reference. I am using HDF5 1.10.3. Thanks in advance.

#define REAL float
#define H5T_NATIVE_RL H5T_NATIVE_FLOAT
#define MPI_RL MPI_FLOAT

#define RANK 2
#define PAR_RANK 3
#define LENLINE 4096
#define MAXLEN 256
#define DOMAINDATA 6
#define GRIDDATA 6
#define MAXFILE 20000

hid_t vdcpl_id; 
hid_t vds_space_id; 
 hid_t src_dataspace_id;
 hid_t vdset_id; 
 hsize_t vdims[PAR_RANK];
 hsize_t src_dims[PAR_RANK];
 hsize_t voffset[PAR_RANK];
 hsize_t vcount[PAR_RANK];
 hsize_t vstride[PAR_RANK];
 hsize_t vblock[PAR_RANK];

 vdcpl_id = H5Pcreate(H5P_DATASET_CREATE);

 vdims[0] = 49152;
 vdims[1] = 21;
 vdims[2] = iEndFrame-iStartFrame+1;

 vds_space_id = H5Screate_simple(PAR_RANK, vdims, NULL);

 offset[0] = 0;
 offset[1] = 0;
 offset[2] = 0;

 count[0] = 1;
 count[1] = 1; 
 count[2] = 1;

 stride[0] = 1;
 stride[1] = 1;
 stride[2] = 1;

 block[0] = 49152;
 block[1] = 21;
 block[2] = 1;

 src_dims[2] = 1;
 src_dims[1] = 21;
 src_dims[0] = 49152;

for(i=iStartFrame; i<=iEndFrame; i++)


 frameIndex = i - iStartFrame;
 voffset[0] = 0;
 voffset[1] = 0;
 voffset[2] = frameIndex;

 vstride[0] = 1;
 vstride[1] = 1;
 vstride[2] = 1;

 vblock[0] = 49152;
 vblock[1] = 21;
 vblock[2] = 1;

 vcount[0] = 1;
 vcount[1] = 1; 
 vcount[2] = 1;

 src_dataspace_id = H5Screate_simple(PAR_RANK, src_dims, NULL);

 H5Sselect_hyperslab(src_dataspace_id, H5S_SELECT_SET, offset, stride, block, count);

 H5Sselect_hyperslab(vds_space_id, H5S_SELECT_SET, voffset, vstride, vblock, vcount);

 sprintf(hdf5FileName, "ParData.%s.%d.h5",probName,frameIndex);

 sprintf(parDSetName, "/Particles/particle_%d", frameIndex );

 status = H5Pset_virtual(vdcpl_id, vds_space_id, hdf5FileName, parDSetName, src_dataspace_id);

 if(status < 0)
 printf("Proc:%04d ************** Failed creating virtual mapping %s ****************nn",
 my_id, hdf5FileName);
 return 1;
 

 printf("Proc:%04d ************** Creating virtual mapping %s ****************nn",
 my_id, hdf5FileName);

 H5Sclose(src_dataspace_id);



sprintf(hdf5FileName, "ParData.%s.0.h5",probName);


file_id = H5Fopen(hdf5FileName, H5F_ACC_RDWR, H5P_DEFAULT);


/* Create VDS in the 0th frame HDF5 file inside the Particles Grp. */
parGrp_id = H5Gopen1(file_id, "/Particles");

vdset_id = H5Dcreate(parGrp_id, "VDS", H5T_NATIVE_RL, vds_space_id, H5P_DEFAULT,
 vdcpl_id, H5P_DEFAULT);

H5Sclose(vds_space_id);
H5Gclose(parGrp_id);
H5Dclose(vdset_id);
H5Pclose(vdcpl_id);
H5Fclose(file_id);