All the utility codes (hdf5_merge, hdf5_extract, & hdf5_double_to_single) could be built on ET and could do someting e.g. merging chunked data but they don't seem to match with current Carpet HDF5 format. I couldn't open the combined file with Visit.

I made a build by locating the old util directory to ExternalLibraries/HDF5/src with very minor tweak. Not by build with the old CactusExternal/HDF5.

Hee Il