> How can I get such a log file otherwise?

rsync ... >> logfile
is good enough for me. Or:
--log-file=FILE log what we're doing to the specified FILE
--log-file-format=FMT log updates using the specified FMT

> BTW: Does rsync delete remote files (from previous rsync operations) if
> they are not existing
> any more on the source system ?

--delete delete extraneous files from dest dirs
--
Guillaume Dargaud
http://www.gdargaud.net/