diff --git a/src/h5core/h5_attach.c b/src/h5core/h5_attach.c
index 92f2cea..65d1696 100644
--- a/src/h5core/h5_attach.c
+++ b/src/h5core/h5_attach.c
@@ -12,6 +12,86 @@ open_space_all (
 	return H5S_ALL;
 }
 
+/*
+  experimental code, will replace  h5priv_write_dataset_by_name() somewhen
+*/
+write_dataset_by_name (
+ 	h5_file_t* const f,
+	const hid_t loc_id,
+	h5_dsetobject_t* dset
+	) {
+	H5_PRIV_API_ENTER (h5_err_t);
+	h5_info ("Writing dataset %s/%s.",
+		 hdf5_get_objname (loc_id), dset->name);
+
+	h5_err_t exists;
+	TRY (exists = hdf5_link_exists (loc_id, dsinfo->name));
+	if ((exists > 0) && ((f->mode==H5_O_WRONLY) || (f->mode==H5_O_APPEND))) {
+		h5_warn ("Dataset %s/%s already exist.",
+			 hdf5_get_objname (loc_id), dsinfo->name);
+		H5_PRIV_API_LEAVE (h5priv_handle_file_mode_error(f->mode));
+	}
+
+	/*
+	  open/create dataset
+	*/
+	hid_t dset_id;
+	hid_t dataspace_id;
+	hid_t diskspace_id;
+	hid_t memspace_id;
+
+	if (exists) {
+		/* overwrite dataset */
+		TRY (dset_id = hdf5_open_dataset (loc_id, dsinfo->name));
+		TRY (dataspace_id = hdf5_get_dataset_space (dset_id));
+		TRY (hdf5_set_dataset_extent (dset_id, dsinfo->dims));
+		/* exten dataset? */
+	} else {
+		/* create dataset */
+		TRY (dataspace_id = hdf5_create_dataspace (
+			     dsinfo->rank,
+			     dsinfo->dims,
+			     dsinfo->max_dims));
+		TRY (dset_id = hdf5_create_dataset (
+			     loc_id,
+			     dsinfo->name,
+			     dsinfo->type_id,
+			     dataspace_id,
+			     dsinfo->create_prop));
+	}
+	TRY (memspace_id = (*set_memspace)(f, 0));
+	TRY (diskspace_id = (*set_diskspace)(f, dataspace_id));
+#ifdef PARALLEL_IO
+	TRY (h5_start_throttle (f));
+#endif
+	TRY (hdf5_write_dataset (
+		     dset_id,
+		     dsinfo->type_id,
+		     memspace_id,
+		     diskspace_id,
+		     f->xfer_prop,
+		     data));
+#ifdef PARALLEL_IO
+	TRY (h5_end_throttle (f));
+#endif
+	TRY (hdf5_close_dataspace (diskspace_id));
+	TRY (hdf5_close_dataspace (memspace_id));
+	TRY (hdf5_close_dataset (dset_id));
+	f->empty = 0;
+
+	H5_PRIV_API_RETURN (H5_SUCCESS);
+}
+
+/*
+  - on all procs create dataset with given size of content
+  - create diskspace
+  - set hyperslap on diskspace:
+     - select all on proc 0
+     - select 0 byte on proc > 0
+  - create memspace with size of selection
+  - write 
+  - close objects
+*/
 h5_err_t
 h5_write_attachment (
 	h5_file_t* const f,
@@ -23,34 +103,39 @@ h5_write_attachment (
 	H5_CORE_API_ENTER4 (h5_ssize_t,
 			    "name=\"%s\", type=%ld, content=0x%p, size=%llu",
 			    name, (long)type, content, (unsigned long long)size);
-	// write only on proc 0
-	if (f->myproc != 0) {
-		H5_CORE_API_LEAVE (H5_SUCCESS);
-	}
-	hid_t group_id;
-	TRY (group_id = h5priv_open_group (f, f->file, H5_ATTACHMENT));
-	h5_err_t exists;
-        TRY (exists = hdf5_link_exists (group_id, name));
-	if (exists > 0) {
-		// warn user on overwrite
-		h5_warn ("Dataset %s/%s already exists",
-			 hdf5_get_objname(group_id), name);
-	}
 	h5_dsinfo_t dsinfo;
 	strncpy (dsinfo.name, name, sizeof (dsinfo.name) - 1);
 	dsinfo.rank = 1;
-	dsinfo.dims[0] = size;
-	dsinfo.max_dims[0] = size;
 	dsinfo.type_id = type;
 	dsinfo.create_prop = f->create_prop;
 	dsinfo.access_prop = f->access_prop;
+
+	hid_t group_id;
+	TRY (group_id = h5priv_open_group (f, f->file, H5_ATTACHMENT));
+
+	h5_err_t exists;
+        TRY (exists = hdf5_link_exists (group_id, name));
+	// write only on proc 0
+	if (f->myproc != 0) {
+		// write on proc 0 only
+		dsinfo.dims[0] = size;
+		dsinfo.max_dims[0] = size;
+		if (exists > 0) {
+			h5_warn ("Dataset %s/%s already exists",
+				 hdf5_get_objname(group_id), name);
+		}
+	} else {
+		// write 0 bytes on all other procs
+		dsinfo.dims[0] = 0;
+		dsinfo.max_dims[0] = 0;
+	}
 	TRY (h5priv_write_dataset_by_name (
-		f,
-		group_id,
-		&dsinfo,
-		open_space_all,
-		open_space_all,
-		content));
+		     f,
+		     group_id,
+		     &dsinfo,
+		     open_space_all,
+		     open_space_all,
+		     content));
 	TRY (hdf5_close_group (group_id));
 	H5_CORE_API_RETURN (H5_SUCCESS);
 }