}
rrdnew.stat_head->float_cookie = rrd_file->file_len +
(rrdold.stat_head->ds_cnt * sizeof(rrd_value_t) * modify);
- rrd_out_file = rrd_open(outfilename, &rrdnew, RRD_READWRITE | RRD_CREAT);
+ rrd_out_file = rrd_open(outfilename, &rrdnew, RRD_READWRITE | RRD_CREAT | RRD_CREAT_SETSIZE);
if (rrd_out_file == NULL) {
rrd_set_error("Can't create '%s': %s", outfilename,
rrd_strerror(errno));