Hello, If its near 2 m, I doubt it will be a carry on, you can ask but most prob be luggage, as for length, you should be able to get most anything on, I've traveled with surfboards heaps, my board bag was 8 ft and had 3 boards in it, there was allways people with bigger ones,
one tip is don't put heaps of " Fragile " stickers on it, it will only provoke the blokes to chuck it higher and harder or run a forklift through it, have a nice flight,
Cheers, where ya goin?