You can also, what I did, switch dropbox off and switch it on only when you are connected to power for a sync. It's not ideal, but it works. I don't see how dropbox could do better though. If you do it manually to your NAS, you basically do the same as switching dropbox on/off or dropbox in a cronjob. Anything monitoring your file system and synching up with many small files will incur load like this.

I use ControlPlane - http://www.controlplaneapp.com/ - which monitors your "context" (like location etc.) and lets you trigger events on context change.

Just added some rules so that Dropbox quits when I'm in my "mobile" context, but reopens when I am in my "home" or "office" contexts. Will see whether it works on my commute later.

Nice! Thanks for that tip.

And I'll note that after my commute home, I do seem to have a bit more battery life than usual. So that's a win.

It already exists, it's called git annex. It uses git to keep track of where files are (but doesn't check them in), so you can just do:

  $ git annex add myfile
  $ git annex copy --to=NAS myfile
  $ git annex get myotherfile
  $ git annex drop --from=NAS myotherfile

If the NAS has rsync support, you can add it with a single command:

  $ git annex initremote NAS type=rsync \
    rsyncurl=rsync://example.com/myrsync encryption=<gpg-email>

http://git-annex.branchable.com/

Thanks! I'm taking a look at this now.

git repo outside of dropbox to store code and changes, but use dropbox to share project files like docs etc. Works well.