Use DropBox to keep Multiple Computers in Sync

by Kelle on December 23, 2009

Dropbox Logo
In my current work setup, I have two offices and, like many astronomers, multiple computers. While ideally, my MacBook Air is my primary machine, DropBox has enabled me to get my most vital data and applications (1Password, Things, and BibDesk) synced up between my laptop and home and office desktop computers.

This is Part 1 of a two-part series. This entry is all about DropBox while in in Part 2, I’ll describe how I’m using Fruux to keep my iCal and Address Book (and Google Contacts) all in sync. But for the moment, read on to find out all the ways I use DropBox!

First, a disclaimer. Keeping things in sync across multiple computers is a tricky business. Before playing around with anything, BACKUP, ensure that you understand what you expect to happen on all the computers, and do things one step at a time. Once syncing is setup, the best practice is to quit apps that are accessing a synced file that you might access from another computer. So, bottom line, BACKUP, don’t go forth blindly, be cautious, and always quit/close synced applications/documents when leaving your home/office/lab computer. Alright, now that that is out of the way…

DropBox is a magical service that enables you to sync, share, and backup files across platforms, including the iPhone, via the cloud. The first 2 GB of storage are free and there is a monthly fee for up to 100 GB. In addition to accessing your personal files, DropBox is also a great alternative to FTP and email attachments for sharing large files (including .mp3s) with collaborators. On the iPhone, if you mark a file as a Favorite, it will be stored locally and accessible when your offline. (I use this feature to keep the NYC bus map at my fingertips.)

The best workflow I’ve settled on is maintaining a traditional directory structure on my primary computer (Sarah, the MacBook Air head) and putting symbolic links (with SymbolicLinker) to the directories I want to sync (e.g., Proposals/, Pubs In Progress/, Observing Runs/, AstroBetter/) in DropBox/. On the secondary computers (Sonia, the office iMac, and Nancy, the home Mac Mini), the DropBox/ folder functions as my Documents/ folder.

1passwordIn addition to just documents, DropBox can help you keep applications in sync as well. I’ve found that the most useful app to keep synced up is 1Password, for its superb password management, seemless integration with most web browsers, and iPhone app. With DropBox keeping your 1Password database in sync, you can create a new login at work and use it at home without writing anything down (or even ever seeing the automatically generated password). The trick is to simply move 1Password’s keychain file to DropBox/ from its default location in ~/Library/Application Support/ on all of the Macs and then point 1Password to the new location in Preferences > General > DataFile. I only sync the 1Password iPhone app with my primary computer, but I don’t think it would be a problem to sync with the secondary computers. Update 2/15/2010: Syncing on the secondary computers totally works.

thingsAnother app that I use almost everyday on multiple computers is my favorite task manager, Things. Similar to 1Password, all you have to do is move the Things database from ~/Library/Application Support/Cultured Code/ to DropBox/. To point Things to the new location, launch the app while holding down the Option/Alt key. Two things to be aware of: 1) never have Things open at two locations at once or the database might become corrupted and 2) if you use the AutoUpdate feature to update to a new version of Things on one computer, you will likely have to update by hand on the other computers before it will open the database that was “created by a newer version.” Again, I only sync Things on my iPhone with my primary computer, but syncing with the secondary computers would probably work. Update 2/15/2010: Syncing on the secondary computers totally works.

BibdeskBibDesk is another app that’s useful to keep in sync (especially since I read astro-ph at home on a secondary computer in the mornings). In my installation of LaTeX, the .bib file lives in ~/Library/texmf/bibtex/bib/ and since I want it to remain here for BibTex to find, I simply made a symbolic link to it in DropBox/. To keep the PDF library in sync is a little trickier: First, quit DropBox on all computers. On the primary computer, put a symbolic link to /Documents/Papers/ in Dropbox/, open and sync DropBox on the primary computer. Open DropBox on the secondary computers and wait for them to finish syncing. Finally, on the secondary computers, put a symbolic link in Documents/ to DropBox/Papers (the opposite of what’s on the primary computer). On all of the computers, I autofile PDFs to /Documents/Papers/ and, so far, it works beautifully!

In Part 2, I’ll describe how I got Fruux to keep my iCal and Address Book (and Google Contacts) all in sync.

How do you use DropBox? Let’s hear it in the comments!

DropBox (free)

{ 8 comments… read them below or add one }

1 Ben Maughan December 23, 2009 at 12:58 pm

I use dropbox for a few bits and pieces, but to keep most of my data in sync between my linux desktop and macbook air, I’ve been using unison for the past 2 years. It’s very reliable, with a useful gui and works on mac (available via macports), linux and windows.

This has the advantage that any sensitive data is not kept on someone elses server, is free, and there is no size limit.


2 Sarah December 24, 2009 at 11:24 am

Dropbox is really great. I constantly switch between linux and windows and it helps keep everything synced. The Public folder is really handy for sending big files to colleagues without having to set up ftp directories or clog people’s inboxes with large attachments. Things is a lovely programme for task management, I’m jealous of you Mac-ites! Why not for Windows? 🙁


3 Christopher January 9, 2010 at 4:20 am

Thanks for writing this article. I don’t yet have a sync workflow between my two computers and really, really need to change that. Interested to see the discussion that follows…


4 Tom January 11, 2010 at 10:38 am

Dropbox is awesome, I started using it for 1Password and BibTeX, but I’m now using it as a repository for presentations and papers as well as things like job applications and CV.


5 Denis Brennan April 18, 2010 at 5:20 pm

How do I create the symlink? Do I just right-click on the folder inside dropbox and choose services, symlink etc…? I have already put the folder in question inside Dropbox. If I do as described above and edit a file in the folder locally (in OSX/User/Documents) , does symlink ensure I have a synched copy in Dropbox?


6 Kelle April 18, 2010 at 6:10 pm

@Denis. A symbolic link is just a pointer…Here’s a wiki article that might help: But to answer your question, yes, right click, Services, Make Symbolic Link. And yes, having the symbolic link either 1) in DropBox pointing to the local folder or 2) in Documents pointing to Dropbox will ensure Dropbox can see it and sync it.


7 Kyle October 19, 2010 at 3:26 pm

Exactly the tip I was looking for – a triple thank you to Kelle, AstroBetter, and the Googles.


8 Mispeld Skolar February 28, 2012 at 12:16 pm

Just followed your tips to keep academic papers, .bib files, and the /Documents/Papers folder all in sync. HUGE HELP. Thank you!


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