[Libguestfs] Help: host system got very slow when run guestfish

[Pino]

Hi there,
     Recently, I got a strange phenomenon, when I run:

	./run guestfish -a xxx.img -a xxx.img

     My host system got to be very very slow for several minites, 
sometimes can`t even move my mouse. I am not sure what I have done made 
it this way.
     How should I investigate this issue? Because I don`t see anyone got 
this kind of problem in FAQ

     Thanks in advance.

Yours Sinerely,

Pino Tsao