>>what is supposed to stop 2 copies running at the same time, I assume the
>>logic in fb_server is something like
>>if lock_mgr is not running (determined how?) then start one
>
> I don't know the answer - but Vlad watches this list from time to time and he'll be able to explain it (I think!)

Yes, Vlad watches but he is not a real Linux man ;)

AFAIU, Milan already gave correct answer on question how more than one instance of fb_lock_mgr
may runs simultaneously. For more detailed explanations, if someone need it, welcome to fb-devel.

Regards,
Vlad