I'm not in love with my solution, I consider it like a stone to "thump" on the door of the monastery of wisdom. Once I find what could solve the problem in the best and easy way, I'd probably throw it away :) This just to say that I feel quite positively prepared to criticism, and to thank you (and tlm) for the feedback.

I have complete control over the CPU of my laptop. Moreover, most of the time I'm behind a proxy in an enterprise I work for as a consultant, so I wouldn't have occasion to control servers remotely in a comfortable way. This is why I do most of these calculations on my laptop - and why I'd like to arrive home and restart the process during the night :)

Moreover, my current setup does not allow me to suspend and resume the laptop easily. This led me to try to code something: just because the particular issue could pop up in non-Unix world, or in situations where your suggestions could not be followed easily. In one word: when portability could be an issue (which I agree that is not something that happens every time :).