If you have the choice, don’t. Pick one and stick with it. My personal preference at this time is git because it facilitates smaller commits — but who cares what I prefer, you’re probably tied to a versioning system based on what someone long before you decided to use.
I for one am tied to svn for doing deploys, but since I’m gaga over git and doing things in the open, I want to use git on a day to day basis and just use svn for deploys.
This sucks, but if you’re going to do it, you shouldn’t be a douche and add your .git directory to svn. That was my first attempt, even though I knew it was bad, I wanted to see the performance hit on svn firsthand I guess.
So I have the deployment related files in svn, so git is free of any environment specific files, like database configs.
So I do all development in git with “.svn” in the .gitignore. That part is easy. Getting svn to ignore git is a little more annoying, especially if you have multiple submodules. So when you’re ready, you add everything to svn, then rm the .git files. It’s better to rm them with the –keep-local flag.
If you delete the .git files because you forgot to –keep-local, or, more likely you’ve had to blow away your development and bring it back via svn, then you have to restore the .git files. Restoring them isn’t so bad:
git init
git remote add origin git@github.com/your_project.git
git pull origin master