Stories about Software


Version Control Beyond Code

One of my favorite OSS tools is Subversion. I’ve used it a great deal professionally for managing source code, and it’s also the tool of choice for my academic collaborations between students not located on campus (which describes me, since my MS program is an online one). It seems a natural progression from CVS, and I haven’t really tried out GIT yet, so I can’t comment as to whether or not I prefer that mode of development.

However, I have, over the last few years, taken to making use of subversion for keeping track of my documents and other personal computing items at home, and I strongly advocate this practice for anyone who doesn’t mind the setup overhead and sense of slight overkill. Before I describe the subversion setup, I’ll describe my situation at home. I have several computers that I use for various activities.  These computers include a personal desktop, a personal netbook, sometimes a company laptop, and a handful of playpen machines running various distros of Linux. I also have a computer that I’ve long since converted into a home server — an old P3 with 384 megs of RAM running Fedora. Not surprisingly, this functions as the subversion server.

One of the annoyances of my pre-personal-subversion life was keeping files in sync. I saw no reason that I shouldn’t be able to start writing a document on my desktop and finish it on my laptop (and that conundrum applies to anyone with more than one PC, rather than being specific to a computer-hoarding techie like me). This was mitigated to some degree by setting up a server with common access, but it was still sort of clunky.

So, I decided to make use of subversion for keeping track of things. Here is a list of advantages that I perceive to this approach:

  • Concurrent edits are not really an issue
  • Creates a de facto backup scheme, since subversion stores the files in its repository and requires them to exist on at least one additional machine for editing
  • Combined with tortoise client for windows, allows you to see which folders/files have been edited since you ‘saved’ changes to the repository Modified subversion folder
  • You can delete local copies of the files and then get them back again by running an update — handy for when you want to work on collaborated stuff but not take up local space. This beats the central storage model, particularly with a laptop, because you can work on a file not on your home network without missing a beat
  • You have a built-in history of your files and can revert to any previous version you like at any time. This is useful for backing up something like Quicken data files that continuously change. Rather than creating hundreds of duplicate files to log your progress over time, you just worry about one and let subversion handle the history.
  • You can easily create permissions as to who has access to what without worrying about administering windows DNS, workgroups, fileshares, and other assorted IT minutiae.
  • Whether you were originally or not, this gives you bonafide experience as an SVN administrator

On the other hand, there are some disadvantages, though I don’t consider them significant:

  • Requires riding the SVN admin learning curve.
  • Requires a server for the task (practically anyway — you can always turn a PC into a SVN server with the file based mode, but I’m not a huge fan)
  • Can be overkill if you don’t have a lot of files and/or sharing going on

So, I would say that the disadvantages apply chiefly to those unfamiliar with SVN or without a real need for this kind of scheme. Once it’s actually in place, I’m hard pressed to think of a downside, and I think you’ll come to find it indispensable.

To set this up, you really only need a server machine and TortoiseSVN (windows) or a subversion client for Linux. I won’t go into the details of server setup with this post, but suffice it to say that you set up the server, install the clients, and you can be off and running. If there is some desire expressed in comments or I get around to it, I can put up another post with a walkthrough of how to set up the server and/or the clients. Mine runs over the HTTP protocol, and I find this to be relatively robust compared to the file protocol and non-overkill compared to the secure protocol involving keys. (Since this is a local install and my wireless network is encrypted with WPA-PSK, I’m not really worried about anyone sniffing the transfers.)