Thanks Oleg for your answer.
Actually I'm in vacation so I can't give you precise details. We are having problems with a manufacturing semiconductor 
equipment (resist removal) which has as the main computer a QNX 4.25 OS. Because this Novellus equipment is quite old, 
we suspect that the hard disk or the application installed are not functioning properly any more. We have random SECS 
disconnections. So before doing anything, we planned to do at least an hard disk image. My colleague called me home to 
have some help but nobody of us in fact knows this OS. I found on the web that Ghost supports this kind of file system 
and can be used to do images . As soon as I finish my vacation, I'll let you know how this issue is evolving. 
I thanks you again for your time and answer.