Melde Dich doch mal per ssh an Deiner DiskStation an und gib "s2s_monitor -h" ein.
Kriege dann folgende Antwort:
DiskStation> s2s_monitor -h
Wait for a particular event on a file or set of files.
Usage: inotifywait [ options ] file1 [ file2 ] [ file3 ] [ ... ]
Options:
-h|--help Show this help text.
@<file> Exclude the specified file from being watched.
--exclude <pattern>
Exclude all events on files matching the
extended regular expression <pattern>.
--excludei <pattern>
Like --exclude but case insensitive.
-m|--monitor Keep listening for events forever. Without
this option, inotifywait will exit after one
event is received.
-d|--daemon Same as --monitor, except run in the background
logging events to a file specified by --outfile.
Implies --syslogg.
-r|--recursive Watch directories recursively.
--fromfile <file>
Read files to watch from <file> or `-' for stdin.
-o|--outfile <file>
Print events to <file> rather than stdout.
-s|--syslogg Send errors to syslogg rather than stderr.
-q|--quiet Print less (only print events).
-qq Print nothing (not even events).
--format <fmt> Print using a specified printf-like format
string; read the man page for more details.
--timefmt <fmt> strftime-compatible format string for use with
%T in --format string.
-c|--csv Print events in CSV format.
-t|--timeout <seconds>
When listening for a single event, time out after
waiting for an event for <seconds> seconds.
If <seconds> is 0, inotifywait will never time out.
-e|--event <event1> [ -e|--event <event2> ... ]
Listen for specific event(s). If omitted, all events are
listened for.
Exit status:
0 - An event you asked to watch for was received.
1 - An event you did not ask to watch for was received
(usually delete_self or unmount), or some error occurred.
2 - The --timeout option was given and no events occurred
in the specified interval of time.
Events:
access file or directory contents were read
modify file or directory contents were written
attrib file or directory attributes changed
close_write file or directory closed, after being opened in
writeable mode
close_nowrite file or directory closed, after being opened in
read-only mode
close file or directory closed, regardless of read/write mode
open file or directory opened
moved_to file or directory moved to watched directory
moved_from file or directory moved from watched directory
move file or directory moved to or from watched directory
create file or directory created within watched directory
delete file or directory deleted within watched directory
delete_self file or directory was deleted
unmount file system containing file or directory unmounted
DiskStation>
Ob Dir das weiterhilft weiß ich nicht, habs selber noch nicht ausprobiert. Hab mich in die ganze Materie noch nicht wirklich eingearbeitet.
Würde aber auch gerne eine Nachricht vom DSM kriegen, wenn jemand per Webdav zugreift oder wenn sich in dem einen oder anderen Ordner was tut.
Ob die Benachrichtigung nun per mail, growl oder prowl kommt, wäre mir ziemlich egal. Alle drei Möglichkeiten sind eingerichtet und laufen auch.
Edit:
Wühle mich grade im AdminTool durch die Commands Reference. Was ein Spaß

Glaube da kann man alle Tools finden, um das zu bewerkstelligen, was ich will.
Hab zwar noch nie ein Script geschrieben, das höchste der Gefühle war ein kleiner Dienst im Automator, doch jetzt hat mich ein bißchen der Ehrgeiz gepackt.