[[!comment format=mdwn
 username="CandyAngel"
 subject="comment 2"
 date="2015-10-15T10:59:59Z"
 content="""
*migrate* takes the *--force* option (introduced 5.20150327), allowing you to migrate files to the backend they are already using, but using the new extension. It was actually added for this use case!

This may still incur a hash of the file though as, I believe, *migrate* will check the file at the old key is valid. You will also end up with 2 versions of the file in .git/annex/objects though (you can clean it up with *unused*).
"""]]