What id like to know is: can i simply use fossil or do i need fossil+venti?
Yes, but then you wont have permanent snapshots, I very much recommend using venti, among other reasons because even in case of your fossil getting corrupted (which is not unheard of, specially if you run out of space), you can always restore the last snap from venti.
can backup period (currently daily) be set to stg. else? Like every two hours?
Yes, see fossilcons(8), in particular the snaptime command, but you probably should read the whole man page to get a better idea of how things work. Best wishes uriel
