This is true, but anything can happen while futzing with a file. Our method is to make a copy of the file with a .tmp extension, make your mods, then rename th

This is true, but anything can happen while futzing with a file. Our method is to make a copy of the file with a .tmp extension, make your mods, then rename the file and delete the old one. HDF5 was never intended be be a container used to stream data into -- it was meant for sharing data.