Migrating a complex branch hierarchy from SVN to Git

How can a large SVN repository (several GBs) with hundreds of branches be migrated to a Git repository? Not looking for them to work side by side, just a way to get rid of SVN.

From some experiments I've done with git svn it's not clear how to specify a complex branch hierarchy. Especially when branches often get deleted in SVN...

Here's an example of the sort of hierarchy I'm talking about:

trunk/
tags/
vendors/boost/
branches/ProjectA/
branches/ProjectA/MajorVers开发者_运维问答ion/
branches/ProjectA/MajorVersion/MinorVersion/
branches/Experimental1/
branches/RecycleBin/OldDiscardedBranch

The point being that a simple regex or wildcard cannot capture the correct location of all branches.

Is there a way to feed all these branch location information to Git? What will git-svn do when it tries to migrate a revision that belongs to a deleted branch?

I've been looking at doing similar things with a different repo. The end result of my thinking and playing is that you need to do a few things:

• Use git filter-branch to do rewriting from some projects to another. IE, use git filter-branch to rename everything in a sub-directory to a parent. In my case, I have multiple modules under trunk and I'm using filter-branch to move everything inside one directory to the top.
• Do this for each branch as well, but also delete any branches that don't pertain to a particular project

That way in the end you'll have multiple git repos that contain only one project per repo (the way it should be).

If the branching/tags directories are complex, the git svn clone command will let you specify multiple tag and branch directories using a comma (if I recall).

Also, run git gc --aggressive after you've finished extracting everything to shrink the repo size a bit.