[[forum/tips:_special__95__remotes__47__hook_with_tahoe-lafs]] is a good
start, but Zooko points out that using Tahoe's directory translation layer
incurs O(N^2) overhead as the number of objects grows. Also, making
hash subdirectories in Tahoe is expensive. Instead it would be good to use
it as a key/value store directly. The catch is that doing so involves
sending the content to Tahoe, and getting back a key identifier.

This would be fairly easy to do as a [[backend|backends]], which can assign its
own key names (although typically done before data is stored in it),
but a tahoe-lafs special remote would be more flexible.

To support a special remote, a mapping is needed from git-annex keys to
Tahoe keys.

The best place to store this mapping is perhaps as a new field in the
location log:

	date present repo-uuid newfields

This way, each remote can store its own key-specfic data in the same place
as other key-specific data, with minimal overhead.
