iowatcher usage:
	-d (--device): device for blktrace to trace
	-D (--blktrace-destination): destination for blktrace
	-t (--trace): trace file name (more than one allowed)
	-F (--fio-trace): fio bandwidth trace (more than one allowed)
	-l (--label): trace label in the graph
	-o (--output): output file name for the SVG image or video
	-p (--prog): run a program while blktrace is run
	-K (--keep-movie-svgs keep svgs generated for movie mode
	-m (--movie [=spindle|rect]): create IO animations
	-C (--codec): ffmpeg codec. Use ffmpeg -codecs to list
	-r (--rolling): number of seconds in the rolling averge
	-T (--title): graph title
	-N (--no-graph): skip a single graph (io, tput, latency, queue-depth, 
			iops, cpu-sys, cpu-io, cpu-irq cpu-soft cpu-user)
	-O (--only-graph): add a single graph to the output
	-h (--height): set the height of each graph
	-w (--width): set the width of each graph
	-c (--columns): numbers of columns in graph output
	-x (--xzoom): limit processed time to min:max
	-y (--yzoom): limit processed sectors to min:max
	-a (--io-plot-action): plot given action (one of Q,D,C) in IO graph
	-P (--per-process-io): distinguish between processes in IO graph