[[!comment format=mdwn
 username="joey"
 subject="""comment 2"""
 date="2021-11-12T16:57:15Z"
 content="""
Implemented: `git-annex migrate --remove-size --backend=URL`

Be sure to only run it on files using url keys, since it will also 
remove sizes from other keys. (Or use `--inbackend=URL` with it.)

Do note that `git-annex migrate` can only migrate files whose content
is present. If you have never downloaded those urls, and `git-annex get`
cannot download them now, because their size has changed, you
won't be able to migrate data you don't have. In this case, re-running
`git-annex addurl` with `--relaxed` seems like the only option.
"""]]
