How to deal with partial svn:externals when migrating to Git?

Question

I would like to import a SVN repository into a GitHub Enterprise repository

There are many questions related to this matter and most of them can be addressed either with Git submodules or Git subtree.

In my case I have two repositories:

• The main project repository
• The modules repository (a big SVN repository over 2 GB)

This module repository has the following architecture:

foolib/
   moduleA/
      ...
   moduleB/
      ...
   ...

For the project, only few modules from foolib are used as svn:externals. For example this main project only uses moduleA from foolib.

As mentioned in this question one possible solution is to use sparse-checkout. I'm guessing Git subtree would also do the trick. Unfortunately it doesn't solve the main issue.

If my project is very small, as long as I get something from foolib, even with sparce-checkout, I will retrieve the whole history of foolib (e.g. 2 GB). This issue doesn't exist with SVN because an svn:externals property only fetches what it needs, not the whole history.

I can imagine to do foolish things like recreating a local sparse repository dynamically using the commits listed in git log --follow foolib/moduleA. But I assume this is not a good solution.

What would be the correct workflow to get a similar behavior in Git without having to fetch the whole history of foolib everything I need only few modules?

Sylvan

"one possible solution": to which problem? Where is your git repo? Or are you using git-svn? I am still confused. – Dispermous

@VonC, I've edited my question. The main issue there is with submodules, sparse-checkout or subtree I will always get the whole history of foolib which is huge. I would like to avoid this somehow. – Sylvan

@Dispermous Any news? – Sylvan

Could you consider help.github.com/articles/… in order to isolate each module in its own repo? (once foolib has been imported from SVN into one giant Git repo) – Dispermous

This can help splitting the giant Git repo into smaller ones – Sylvan

Yes, that is the idea. That way, you can define a parent project with, as submodues, only the subrepos you need. – Dispermous