git-annex/ git-annex

NAME

git-annex - manage files with git, without checking their contents in

SYNOPSIS

git annex subcommand [params ...]

DESCRIPTION

git-annex allows managing files with git, without checking the file contents into git. While that may seem paradoxical, it is useful when dealing with files larger than git can currently easily handle, whether due to limitations in memory, checksumming time, or disk space.

Even without file content tracking, being able to manage files with git, move files around and delete files with versioned directory trees, and use branches and distributed clones, are all very handy reasons to use git. And annexed files can co-exist in the same git repository with regularly versioned files, which is convenient for maintaining documents, Makefiles, etc that are associated with annexed files but that benefit from full revision control.

When a file is annexed, its content is moved into a key-value store, and a symlink is made that points to the content. These symlinks are checked into git and versioned like regular files. You can move them around, delete them, and so on. Pushing to another git repository will make git-annex there aware of the annexed file, and it can be used to retrieve its content from the key-value store.

EXAMPLES

# git annex get video/hackity_hack_and_kaxxt.mov
get video/_why_hackity_hack_and_kaxxt.mov (not available)
  I was unable to access these remotes: server
  Try making some of these repositories available:
    5863d8c0-d9a9-11df-adb2-af51e6559a49  -- my home file server
    58d84e8a-d9ae-11df-a1aa-ab9aa8c00826  -- portable USB drive
    ca20064c-dbb5-11df-b2fe-002170d25c55  -- backup SATA drive
failed
# sudo mount /media/usb
# git remote add usbdrive /media/usb
# git annex get video/hackity_hack_and_kaxxt.mov
get video/hackity_hack_and_kaxxt.mov (copying from usbdrive...) ok
# git commit -a -m "got a video I want to rewatch on the plane"

# git annex add iso
add iso/Debian_5.0.iso ok
# git commit -a -m "saving Debian CD for later"

# git annex drop iso/Debian_4.0.iso
drop iso/Debian_4.0.iso ok
# git commit -a -m "freed up space"

# git annex move iso --to=usbdrive
move iso/Debian_5.0.iso (moving to usbdrive...) ok

SUBCOMMANDS

Like many git commands, git-annex can be passed a path that is either a file or a directory. In the latter case it acts on all relevant files in the directory.

Many git-annex subcommands will stage changes for later git commit by you.

  • add [path ...]

    Adds files in the path to the annex. Files that are already checked into git, or that git has been configured to ignore will be silently skipped.

  • get [path ...]

    Makes the content of annexed files available in this repository. Depending on the backend used, this will involve copying them from another repository, or downloading them, or transferring them from some kind of key-value store.

  • drop [path ...]

    Drops the content of annexed files from this repository.

    git-annex may refuse to drop content if the backend does not think it is safe to do so, typically because of the setting of annex.numcopies.

  • unlock [path ...]

    Normally, the content of annexed files is protected from being changed. Unlocking a annexed file allows it to be modified. This replaces the symlink for each specified file with a copy of the file's content. You can then modify it and git annex add (or git commit) to inject it back into the annex.

  • edit [path ...]

    This is an alias for the unlock subcommand. May be easier to remember, if you think of this as allowing you to edit an annexed file.

  • move [path ...]

    When used with the --to option, moves the content of annexed files from the current repository to the specified one.

    When used with the --from option, moves the content of annexed files from the specified repository to the current one.

  • copy [path ...]

    When used with the --to option, copies the content of annexed files from the current repository to the specified one.

    When used with the --from option, copies the content of annexed files from the specified repository to the current one.

  • init description

    Initializes git-annex with a description of the git repository, and sets up .gitattributes and the pre-commit hook.

  • lock [path ...]

    Use this to undo an unlock command if you don't want to modify the files, or have made modifications you want to discard.

  • fsck [path ...]

    With no parameters, this subcommand checks the whole annex for consistency, and warns about any problems found.

    With parameters, only the specified files are checked.

  • unused

    Checks the annex for data that is not used by any files currently in the annex, and prints a numbered list of the data.

  • dropunused [number ...]

    Drops the data corresponding to the numbers, as listed by the last git annex unused

  • find [path ...]

    Outputs a list of annexed files whose content is currently present.

    With no parameters, defaults to finding all files in the current directory and its subdirectories.

  • unannex [path ...]

    Use this to undo an accidental add command. This is not the command you should use if you intentionally annexed a file and don't want its contents any more. In that case you should use git annex drop instead, and you can also git rm the file.

  • uninit

    Use this to stop using git annex. It will unannex every file in the repository, and remove all of git-annex's other data, leaving you with a git repository plus the previously annexed files.

  • fix [path ...]

    Fixes up symlinks that have become broken to again point to annexed content. This is useful to run if you have been moving the symlinks around.

  • pre-commit [path ...]

    Fixes up symlinks that are staged as part of a commit, to ensure they point to annexed content. Also handles injecting changes to unlocked files into the annex.

    This is meant to be called from git's pre-commit hook. git annex init automatically creates a pre-commit hook using this.

  • fromkey file

    This can be used to maually set up a file to link to a specified key in the key-value backend. How you determine an existing key in the backend varies. For the URL backend, the key is just a URL to the content.

    Example:

    git annex fromkey --backend=URL --key=http://www.archive.org/somefile somefile

  • dropkey [key ...]

    This plumbing-level command drops the annexed data for the specified keys from this repository.

    This can be used to drop content for arbitrary keys, which do not need to have a file in the git repository pointing at them.

    A backend will typically need to be specified with --backend. If none is specified, the first configured backend is used.

    Example:

    git annex dropkey --backend=SHA1 7da006579dd64330eb2456001fd01948430572f2

  • setkey file

    This plumbing-level command sets the annxed data for a key to the content of the specified file, and then removes the file.

    A backend will typically need to be specified with --backend. If none is specified, the first configured backend is used.

    Example:

    git annex setkey --backend=WORM --key=1287765018:3 /tmp/file

OPTIONS

  • --force

    Force unsafe actions, such as dropping a file's content when no other source of it can be verified to still exist. Use with care.

  • --quiet

    Avoid the default verbose logging of what is done; only show errors and progress displays.

  • --verbose

    Enable verbose logging.

  • --from=repository

    Specifies a repository that content will be retrieved from. It should be specified using the name of a configured git remote.

  • --to=repository

    Specifies a git repository that content will be sent to. It should be specified using the name of a configured git remote.

  • --exclude=glob

    Skips files matching the glob pattern. The glob is matched relative to the current directory.

  • --backend=name

    Specifies which key-value backend to use.

  • --key=name

    Specifies a key to operate on.

CONFIGURATION

Like other git commands, git-annex is configured via .git/config. Here are all the supported configuration settings.

  • annex.uuid

    A unique UUID for this repository (automatically set).

  • annex.numcopies

    Number of copies of files to keep across all repositories. (default: 1)

  • annex.backends

    Space-separated list of names of the key-value backends to use. The first listed is used to store new files by default. (default: "WORM SHA1 URL")

  • remote.<name>.annex-cost

    When determining which repository to transfer annexed files from or to, ones with lower costs are preferred. The default cost is 100 for local repositories, and 200 for remote repositories.

  • remote.<name>.annex-ignore

    If set to true, prevents git-annex from ever using this remote. This is, for example, useful if the remote is a bare repository, which git-annex does not currently support.

  • remote.<name>.annex-uuid

    git-annex caches UUIDs of repositories here.

  • remote.<name>.annex-scp-options

    Options to use when using scp to or from this repository. For example, to force ipv6, and limit the bandwidth to 1000Kbit/s, set it to "-6 -l 1000"

  • remote.<name>.annex-ssh-options

    Options to use when using ssh to talk to this repository.

  • remote.<name>.annex-rsync-options

    Options to use when using rsync to or from this repository. For example, to force ipv6, and limit the bandwidth to 100Kbyte/s, set it to "-6 --bwlimit 100"

  • annex.scp-options, annex.ssh-options, annex.rsync-options

    Default scp, ssh, and rsync options to use if a remote does not have specific options.

  • annex.version

    Automatically maintained, and used to automate upgrades between versions.

CONFIGURATION VIA .gitattributes

The backend used when adding a new file to the annex can be configured on a per-file-type basis via .gitattributes files. In the file, the annex.backend attribute can be set to the name of the backend to use. For example, this here's how to use the WORM backend by default, but the SHA1 backend for ogg files:

* annex.backend=WORM
*.ogg annex.backend=SHA1

The numcopies setting can also be configured on a per-file-type basis via the annex.numcopies attribute in .gitattributes files. For example, this makes two copies be needed for wav files:

*.wav annex.numcopies=2

FILES

These files are used by git-annex, in your git repository:

.git/annex/objects/ contains the annexed file contents that are currently available. Annexed files in your git repository symlink to that content.

.git-annex/uuid.log is used to map between repository UUID and decscriptions. You may edit it.

.git-annex/*.log is where git-annex records its content tracking information. These files should be committed to git.

.gitattributes is configured to use git's union merge driver to avoid conflicts when merging files in the .git-annex directory.

SEE ALSO

Most of git-annex's documentation is available on its web site, http://git-annex.branchable.com/

If git-annex is installed from a package, a copy of its documentation should be included, in, for example, /usr/share/doc/git-annex/

AUTHOR

Joey Hess joey@kitenet.net

http://git-annex.branchable.com/

Warning: this page is automatically made into a man page via mdwn2man. Edit with care