collectd-iostat.d

#!/usr/sbin/dtrace -s

#pragma D option quiet

io:::start
{
  self->ok = 0;

  /* https://lists.freebsd.org/pipermail/freebsd-dtrace/2015-February/000347.html */
  self->ok = (args[0] != NULL) ? 1 : 0;
}

io:::start
/self->ok && (args[0]->bio_cmd & 0x01)/ /* Read */
{
  @read_bytes[$$1, strjoin(args[1]->device_name, lltostr(args[1]->unit_number))] = sum(args[0]->bio_bcount);
  @write_bytes[$$1, strjoin(args[1]->device_name, lltostr(args[1]->unit_number))] = sum(0);
  @time[$$1, strjoin(args[1]->device_name, lltostr(args[1]->unit_number))] = max(walltimestamp / 1000000000);
}

io:::start
/self->ok && (args[0]->bio_cmd & 0x02)/ /* Write */
{
  @read_bytes[$$1, strjoin(args[1]->device_name, lltostr(args[1]->unit_number))] = sum(0);
  @write_bytes[$$1, strjoin(args[1]->device_name, lltostr(args[1]->unit_number))] = sum(args[0]->bio_bcount);
  @time[$$1, strjoin(args[1]->device_name, lltostr(args[1]->unit_number))] = max(walltimestamp / 1000000000);
}

BEGIN,
END,
tick-$2s
{
  printa("PUTVAL %s/disk-%s/disk_octets-dtrace %@d:%@d:%@d\n", @time, @read_bytes, @write_bytes);
}