To complete the record of this discussion - we added a H5FFlush command after writing every record, group or attribute. In our testing it slows our overall system processing by less than 10% which is acceptable, and we have not had any file corruption after randomly killing the application while it is running, which is a huge improvement. _______________________________________________ Hdf-forum is for HDF software users discussion. Hdf-forum@lists.hdfgroup.org http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org Twitter: https://twitter.com/hdf5