git-annex/doc/not.mdwn

[[!meta title="what git-annex is not"]]

* git-annex is not a backup system. It may be a useful component of an
  [[archival|use_case/bob]] system, or a way to deliver files to a backup
  system. For a backup system that uses git and that git-annex supports
  storing data in, see [[special_remotes/bup]].

* git-annex is not a filesystem or Dropbox clone. However, the git-annex
  [[assistant]] is addressing some of the same needs in its own unique ways.
  (There is also a FUSE filesystem built on top of git-annex, called 
  [ShareBox](https://github.com/chmduquesne/sharebox-fs).)

* git-annex is not unison, but if you're finding unison's checksumming
  too slow, or its strict mirroring of everything to both places too
  limiting, then git-annex could be a useful alternative.

* git-annex is more than just a workaround for git scalability 
  limitations that might eventually be fixed by efforts like
  [git-bigfiles](http://caca.zoy.org/wiki/git-bigfiles). In particular,
  git-annex's [[location_tracking]] allows having many repositories
  with a partial set of files, that are copied around as desired.

* git-annex is not some flaky script that was quickly thrown together.
  I wrote it in Haskell because I wanted it to be solid and to compile
  down to a binary. And it has a fairly extensive test suite. (Don't be
  fooled by "make test" only showing a few dozen test cases; each test
  involves checking dozens to hundreds of assertions.)

* git-annex is not [git-media](https://github.com/schacon/git-media),
  although they both approach the same problem from a similar direction.
  I only learned of git-media after writing git-annex, but I probably
  would have still written git-annex instead of using it. Currently,
  git-media has the advantage of using git smudge filters rather than
  git-annex's pile of symlinks, and it may be a tighter fit for certain
  situations. It lacks git-annex's support for widely distributed storage,
  using only a single backend data store. It also does not support
  partial checkouts of file contents, like git-annex does.

* git-annex is similarly not [git-fat](https://github.com/jedbrown/git-fat),
  which also uses git smudge filters, and also lacks git-annex' widely
  distributed storage and partial checkouts.

* git-annex is also not [boar](http://code.google.com/p/boar/),
  although it shares many of its goals and characteristics. Boar implements
  its own version control system, rather than simply embracing and
  extending git. And while boar supports distributed clones of a repository,
  it does not support keeping different files in different clones of the
  same repository, which git-annex does, and is an important feature for
  large-scale archiving.

* git-annex is not the [Mercurial largefiles extension](http://mercurial.selenic.com/wiki/LargefilesExtension).
  Although mercurial and git have some of the same problems around large
  files, and both try to solve them in similar ways (standin files using
  mostly hashes of the real content).