git-annex-migrate(1) General Commands Manual git-annex-migrate(1)

git-annex-migrate - switch data to different backend

git annex migrate [path ...]

git annex migrate --update

Changes the specified annexed files to use the default key-value backend (or the one specified with --backend). Only files whose content is currently present are migrated.

Note that the content is also still stored using the old keys after migration. When possible, hard links are used to avoid that taking up extra disk space. Use git annex unused to find and remove the old keys.

Normally, nothing will be done to specified files that are already using the new backend. However, if a backend changes the information it uses to construct a key, this can also be used to migrate files to use the new key format.

This updates the local repository for migrations that were performed elsewhere. Only new migrations since the last time this was run will be performed.
This does not modify the working tree, but only hard links (or in some cases copies) annex objects to their new keys.
git-annex pull and git-annex sync --content automatically do this, unless the annex.syncmigrations config is set to false.
Note that older versions of git-annex did not record migrations in a way that this can use. Migrations performed with those older versions had to be manually run in each clone of the repository.
This applies all recorded migrations to the local repository. It is the non-incremental form of --update.
One situation where this can be useful is when git-annex migrate --update has been run, but since then un-migrated objects have entered the repository. Using this option ensures that any such objects get migrated.
Note that older versions of git-annex did not record migrations in a way that this can use. Migrations performed with those older versions had to be manually run in each clone of the repository.
Specify the new key-value backend to use for migrated data.
Force migration of keys that are already using the new backend.
The git-annex-matching-options(1) can be used to specify files to migrate.
Keys often include the size of their content, which is generally a useful thing. In fact, this command defaults to adding missing size information to keys in most migrations. With this option, the size information is removed instead.
One use of this option is to convert URL keys that were added by git-annex addurl --fast to ones that would have been added if that command was run with the --relaxed option. Eg:

git-annex migrate --remove-size --backend=URL somefile
To add back the size to an URL key, use this:
git-annex migrate --backend=URL somefile
Enable JSON output. This is intended to be parsed by programs that use git-annex. Each line of output is a JSON object.
Messages that would normally be output to standard error are included in the JSON instead.

git-annex(1)

git-annex-upgrade(1)

git-annex-backend(1)

Joey Hess <id@joeyh.name>