Look at http://owncloud.org - it's basically a open source dropbox solution.
Don't know what NAS you have but most NAS boxes run on linux and you should be able to get some directions at the owncloud forums.
Otherwise i think Unison or rsync would be the best non server solutions in your case.
This links to a blog post describing the very same problem(and an acceptable solution) but for ubuntu. http://www.cerebralmastication.com/2011/04/fast-two-way-sync-in-ubuntu/
Ok, here is the solution I have found. Whether or not this will work with future versions of Dropbox is uncertain. I have opened a service request with Dropbox to try to resolve the problem further.
Overall, the solution is a combination of two things:
- Setting the umask for the Dropbox process so that newly created files have permissions of 0660. This is user read/write, group read/write, other none.
- Setting the group for newly created files to the group that needs to have write access to the files in question.
This solution will apply to all files in the Dropbox folder, not just a single file. In my case this is acceptable.
Under Linux, I modify the /etc/init.d/dropbox startup script so that the line invoking dropbox as a daemon reads:
HOME="$HOMEDIR" start-stop-daemon --umask 0006 -b -o -c $dbuser:$dbgrp -S -u $dbuser -x $HOMEDIR/$DAEMON
Adding the --umask 0006 accomplishes setting the umask, and the :$dbgrp portion of the -c option accomplishes setting the group to that the daemon belongs to.
On the Mac side, I run the following commands:
ps aux | grep -i dropbox
From this I can see the command-line options that started Dropbox and from this I extract the $mydropboxid used later. Then I quit Dropbox and open a command prompt and enter the following commands:
umask 0006
/Applications/Dropbox.app/Contents/MacOS/Dropbox -psn_0_$mydropboxid &
exit
I plan to automate the above commands at some point so that I won't have to re-run these any time my machine is rebooted.
This handles setting the mask for newly created files so the group for a file has write access. However, in order to get the group set correctly I need to setgid the Dropbox cache directory - this so far has only needed to be done once:
sudo chgrp -R $dbgrp ~/Dropbox/.dropbox.cache
sudo chmod -R g+s ~/Dropbox/.dropbox.cache
It appears that all new files are first created under the ~/Dropbox/.dropbox.cache directory, so the above commands gives those new files the proper ownership and permissions that new files created by Dropbox has the correct group.
Best Answer
There's sthg you could try, it's called DropboxPortableAHK. As the name suggests, it's a portable version of DB. I use it on a Usb key (I cannot install DB on my work desktop).
Even though it's meant to be used on a key, you can put it on your desktop, it'll even use your settings from your actual account if you ask for it during install.
After setting the Sync and go parameter on once for all, you work on your files inside your dropbox folder and have two non-exclusive options: 1)Click on your dropbox app icon as needed to sync the folder. The app will close by itself as soon it's finished its job. You don't need to get out of the db folder while you do that.
2)Set up to launch DbAHk every x minutes from the windows task scheduler . Db will close when the syncing is complete, but you can still continue to work in your local file meanwhile. I just made a test with this function and it does the job.