Thx eric. Everything work well right now. I just don't understand why I needed to change root=/dev/sdxy to readonly. Can you explain please.
In the same time I took the opportunity to partialy ( for now ) translate the 's6,s6-rc,s6-boot,s6opts' thread in Polish. It's for my own learning and if at the same time can help readers, that's good :)
It's here
s6,s6-rc,s6-boot,s6opts: nowa wersja - częściowe tłumaczenie po Polsku