Software upgrades

Upgrading the code base of git-annex will be done differently depending on your install method. For most distribution-based packages, it is handled by the package management software.

For the standalone distribution, the git-annex-webapp(1) will ask the user for confirmation when it detects a new version. Once that is confirmed, or if annex.autoupgrade is enabled (see the git-annex(1) manpage) the assistant will start the upgrade. The upgrade process is fairly simple: the assistant will move the git-annex.linux directory out of the way and replace it with the new version, then re-execute itself. It therefore needs write access to the parent directory of the git-annex.linux directory.

Note that "upgrading" from a distribution-based package to the Linux standalone version may cause weird problems, as an unexpected version of git-annex (e.g. the old one from packages) may be ran, see ?git-annex-shell doesn't work as expected for a full discussion.

Repository upgrades

Occasionally improvements are made to how git-annex stores its data, that require an upgrade process to convert repositories made with an older version to be used by a newer version. It's annoying, it should happen rarely, but sometimes, it's worth it.

There's a commitment that git-annex will always support upgrades from all past versions. After all, you may have offline drives from an earlier git-annex, and might want to use them with a newer git-annex.

git-annex will notice if it is run in a repository that needs an upgrade, and refuse to do anything. To upgrade, use the "git annex upgrade" command.

The upgrade process is guaranteed to be conflict-free. Unless you already have git conflicts in your repository or between repositories. Upgrading a repository with conflicts is not recommended; resolve the conflicts first before upgrading git-annex.

The upgrade process needs to write to the repository. If the original repository cannot be written to (due to eg being on readonly media), the upgrade would need to be run in a copy of the repository.

The upgrade events, so far:

v5 -> v6 (git-annex version 6.x)

The upgrade from v5 to v6 is handled manually for now. Run git-annex upgrade to perform the upgrade.

A v6 git-annex repository can have some files locked while other files are unlocked, and all git and git-annex commands can be used on both locked and unlocked files. (Although for locked files to be accessible, the filesystem must support symbolic links..

Direct mode repositories are upgraded to instead use the new adjusted branches feature, which transparently unlocks all locked files in the local repository.

The behavior of some commands changes in an upgraded repository:

  • git add will add files to the annex, rather than adding them directly to the git repository. To cause some files to be added directly to git, you can configure annex.largefiles. For example:

    git config annex.largefiles "largerthan=100kb and not (include=.c or include=.h)"

  • git annex unlock and git annex lock change how the pointer to the annexed content is stored in git.

There is also a new annex.thin setting, which makes unlocked files in v6 repositories be hard linked to their content, instead of a copy. This saves disk space but means any modification of an unlocked file will lose the local (and possibly only) copy of the old version. This is automatically enabled when upgrading a direct mode repository, since direct mode made the same tradeoff.

See unlocked files for more details about locked files and thin mode.

v4 -> v5 (git-annex version 5.x)

The upgrade from v4 to v5 is handled automatically, and only affects direct mode repositories.

This upgrade involves changing direct mode repositories to operate with core.bare=true.

v3 -> v4 (git-annex version 4.x)

v4 was only used for direct mode, to ensure that a version of git-annex that understands direct mode was used with a direct mode repository.

v2 -> v3 (git-annex version 3.x)

Involved moving the .git-annex/ directory into a separate git-annex branch.

After this upgrade, you should make sure you include the git-annex branch when git pushing and pulling.

tips for this upgrade

This upgrade is easier (and faster!) than the previous upgrades. You don't need to upgrade every repository at once; it's sufficient to upgrade each repository only when you next use it.

Example upgrade process:

cd localrepo
git pull
git annex upgrade
git commit -m "upgrade v2 to v3"
git gc

v1 -> v2 (git-annex version 0.20110316)

Involved adding hashing to .git/annex/ and changing the names of all keys. Symlinks changed.

Also, hashing was added to location log files in .git-annex/. And .gitattributes needed to have another line added to it.

Previously, files added to the SHA backends did not have their file size tracked, while files added to the WORM backend did. Files added to the SHA backends after the conversion will have their file size tracked, and that information will be used by git-annex for disk free space checking. To ensure that information is available for all your annexed files, see SHA size.

tips for this upgrade

This upgrade can tend to take a while, if you have a lot of files.

Each clone of a repository should be individually upgraded. Until a repository's remotes have been upgraded, git-annex will refuse to communicate with them.

Start by upgrading one repository, and then you can commit the changes git-annex staged during upgrade, and push them out to other repositories. And then upgrade those other repositories. Doing it this way avoids git-annex doing some duplicate work during the upgrade.

Example upgrade process:

cd localrepo
git pull
git annex upgrade
git commit -m "upgrade v1 to v2"
git push

ssh remote
cd remoterepo
git pull
git annex upgrade
...

v0 -> v1 (git-annex version 0.04)

Involved a reorganisation of the layout of .git/annex/. Symlinks changed.

Handled more or less transparently, although git-annex was just 2 weeks old at the time, and had few users other than Joey.

Before doing this upgrade, set annex.version:

git config annex.version 0