QNX server backup image

I have a server with qnx 6.5 I want to use dd comand to take full os backup What is right to dd /dev/hd0 or dd /dev/hd07t my aim is to have an image to be applied for other hardware Other concern is if i take dd /dev/hd0 will this produce a file with the same hdd size or the final size will be the data size only