Normally, git-annex repositories consist of symlinks that are checked into git, and in turn point at the content of large files that is stored in .git/annex/objects/. Direct mode gets rid of the symlinks.

The advantage of direct mode is that you can access files directly, including modifying them. The disadvantage is that many regular git commands cannot be used in a direct mode repository, since they don't understand how to update its working tree.

enabling (and disabling) direct mode

Normally, git-annex repositories start off in indirect mode. With some exceptions:

  • Repositories created by the assistant use direct mode by default.
  • Repositories on FAT and other less than stellar filesystems that don't support things like symlinks will be automatically put into direct mode.
  • Windows always uses direct mode.

Any repository can be converted to use direct mode at any time, and if you decide not to use it, you can convert back to indirect mode just as easily. Also, you can have one clone of a repository using direct mode, and another using indirect mode.

To start using direct mode:

git annex direct

To stop using direct mode:

git annex indirect

safety of using direct mode

With direct mode, you're operating without large swathes of git-annex's carefully constructed safety net, which ensures that past versions of files are preserved and can be accessed. With direct mode, any file can be edited directly, or deleted at any time, and there's no guarantee that the old version is backed up somewhere else.

So if you care about preserving the history of files, you're strongly encouraged to tell git-annex that your direct mode repository cannot be trusted to retain the content of a file. To do so:

git annex untrust .

On the other hand, if you only care about the current versions of files, and are using git-annex with direct mode to keep files synchronised between computers, and manage your files, this should not be a concern for you.

use a direct mode repository

You can use most git-annex commands as usual in a direct mode repository.

Direct mode also works well with the git-annex assistant.

The most important command to use in a direct mode repository is git annex sync. This will commit any files you have run git annex add on, as well as files that were added earlier and have been modified. It will push the changes to other repositories for git annex sync there to pick up, and will pull and merge any changes made on other repositories into the local repository.

what doesn't work in direct mode

A very few git-annex commands don't work in direct mode, and will refuse to do anything. For example, git annex unlock doesn't make sense in direct mode.

As for git commands, direct mode prevents using any git command that would modify or access the work tree. So you cannot git commit or git pull (use git annex sync for both instead), or run git status (use git annex status instead). These git commands will complain "fatal: This operation must be run in a work tree".

The reason for this is that git doesn't understand how git-annex uses the work tree in direct mode. Where git expects the symlinks that get checked into git to be checked out in the work tree, direct mode instead replaces them with the actual content of files, as managed by git-annex.

There are still lots of git commands you can use in direct mode. For example, you can run git log on files, run git push, git fetch, git config, git remote add etc.

proxing git commands in direct mode

For those times when you really need to run a command like git revert HEAD in a direct mode repository, git-annex has the ability to proxy the command to work in direct mode.

For example:

git annex proxy -- git revert HEAD

git annex proxy -- git checkout HEAD^^

git annex proxy -- git mv mydir newname

This works by setting up a temporary work tree, letting the git command run on that work tree, and then updating the real work tree to reflect any changes staged or committed by the git command, with appropriate handling of the direct mode files.

undoing changes in direct mode

There is also the undo command to do the equivalent of the above revert in a simpler way. Say you made a change in direct mode, the assistant dutifully committed it and you realise your mistake, you can try:

git annex undo file

forcing git to use the work tree in direct mode

This is for experts only. You can lose data doing this, or check enormous files directly into your git repository, and it's your fault if you do!

Ok, with the warnings out of the way, all you need to do to make any git command access the work tree in direct mode is pass it -c core.bare=false