[[!comment format=mdwn
 username="joey"
 subject="""comment 1"""
 date="2016-09-05T16:40:56Z"
 content="""
This poses difficulties when several different git-annex repositories
are uploading to the same special remote. They would have to somehow maintain a
count of the amount of space used on the remote, but the repositories
could be completely disconnected, other than being able to all access the
special remote. So, the count would have to be stored on the remote, and
updated atomically. But, not all remotes support atomic operations well
enough to support such a distributed counter.

If the storage service has an API call to get the space used, then the
special remote can use that. I think that such a thing unfortunately can
only be implemented that way, on a per-special-remote implementation basis.
"""]]