python - Trouble uploading big file (3Go) with Django

Question

I have a Django application processing files. The uploading process works perfectly for small files (70 Mo). However, an error is raised when I try to upload big files (~3Go) :

Environment:


Request Method: POST
Request URL: http://localhost:8000/import/

Django Version: 1.5.1
Python Version: 2.7.3
Installed Applications:
('django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django_jenkins',
 'libs',
 'bootstrapform',
 'origami',
 'debug_toolbar')
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'debug_toolbar.middleware.DebugToolbarMiddleware')


Traceback:
File "/home/antoine/workspace/server/.virtualenv/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  187.                 response = middleware_method(request, response)
File "/home/antoine/workspace/server/.virtualenv/local/lib/python2.7/site-packages/django/contrib/sessions/middleware.py" in process_response
  38.                     request.session.save()
File "/home/antoine/workspace/server/.virtualenv/local/lib/python2.7/site-packages/django/contrib/sessions/backends/db.py" in save
  51.             session_data=self.encode(self._get_session(no_load=must_create)),
File "/home/antoine/workspace/server/.virtualenv/local/lib/python2.7/site-packages/django/contrib/sessions/backends/base.py" in encode
  86.         pickled = pickle.dumps(session_dict, pickle.HIGHEST_PROTOCOL)

Exception Type: SystemError at /import/
Exception Value: error return without exception set

The upload size limit is set like this : FILE_UPLOAD_MAX_MEMORY_SIZE = 5368709120

Could you tell me if this is a django limitation, or a trouble somewhere on my side ? In the first case, what is the method for uploading large files ?

EDIT : my machine has 14 Go of free RAM when it starts uploading.