The [[walkthrough]] builds up a decentralized git repository setup, but git-annex can also be used with a centralized bare repository, just like git can. This tutorial shows how to set up a centralized repository hosted on GitHub. ## set up the repository, and make a checkout I've created a repository for technical talk videos, which you can [fork on Github](https://github.com/joeyh/techtalks). Or make your own repository on GitHub (or elsewhere) now. On your laptop, [[install]] git-annex, and clone the repository: # git clone git@github.com:joeyh/techtalks.git # cd techtalks Tell git-annex to use the repository, and describe where this clone is located: # git annex init 'my laptop' init my laptop ok Let's tell git-annex that GitHub doesn't support running git-annex-shell there. This means you can't store annexed file *contents* on GitHub; it would really be better to host the bare repository on your own server, which would not have this limitation. (If you want to do that, check out [[using_gitolite_with_git-annex]].) # git config remote.origin.annex-ignore true ## add files to the repository Add some files, obtained however. # youtube-dl -t 'http://www.youtube.com/watch?v=b9FagOVqxmI' # git annex add *.mp4 add Haskell_Amuse_Bouche-b9FagOVqxmI.mp4 (checksum) ok (Recording state in git...) # git commit -m "added a video. I have not watched it yet but it sounds interesting" This file is available directly from the web; so git-annex can download it: # git annex addurl http://kitenet.net/~joey/screencasts/git-annex_coding_in_haskell.ogg addurl kitenet.net_~joey_screencasts_git-annex_coding_in_haskell.ogg (downloading http://kitenet.net/~joey/screencasts/git-annex_coding_in_haskell.ogg ...) (checksum...) ok (Recording state in git...) # git commit -a -m 'added a screencast I made' Feel free to rename the files, etc, using normal git commands: # git mv Haskell_Amuse_Bouche-b9FagOVqxmI.mp4 Haskell_Amuse_Bouche.mp4 # git mv kitenet.net_~joey_screencasts_git-annex_coding_in_haskell.ogg git-annex_coding_in_haskell.ogg # git commit -m 'better filenames' Now push your changes back to the central repository. This first time, remember to push the git-annex branch, which is used to track the file contents. # git push origin master git-annex To git@github.com:joeyh/techtalks.git * [new branch] master -> master * [new branch] git-annex -> git-annex That push went fast, because it didn't upload large videos to GitHub. To check this, you can ask git-annex where the contents of the videos are: # git annex whereis whereis Haskell_Amuse_Bouche.mp4 (1 copy) 767e8558-0955-11e1-be83-cbbeaab7fff8 -- here ok whereis git-annex_coding_in_haskell.ogg (2 copies) 00000000-0000-0000-0000-000000000001 -- web 767e8558-0955-11e1-be83-cbbeaab7fff8 -- here ok ## make more checkouts So far you have a central repository, and a checkout on a laptop. Let's make another checkout that's used as a backup. You can put it anywhere you like, just make it be somewhere your laptop can access. A few options: * Put it on a USB drive that you can plug into the laptop. * Put it on a desktop. * Put it on some server in the local network. * Put it on a remote VPS. I'll use the VPS option, but these instructions should work for any of the above. # ssh server server# sudo apt-get install git-annex Clone the central repository as before. (If the clone fails, you need to add your server's ssh public key to github -- see [this page](http://help.github.com/ssh-issues/).) server# git clone git@github.com:joeyh/techtalks.git server# cd techtalks server# git config remote.origin.annex-ignore true server# git annex init 'backup' init backup (merging origin/git-annex into git-annex...) ok Notice that the server does not have the contents of any of the files yet. If you run `ls`, you'll see broken symlinks. We want to populate this backup with the file contents, by copying them from your laptop. Back on your laptop, you need to configure a git remote for the backup. Adjust the ssh url as needed to point to wherever the backup is. (If it was on a local USB drive, you'd use the path to the repository instead.) # git remote add backup ssh://server/~/techtalks Now git-annex on your laptop knows how to reach the backup repository, and can do things like copy files to it: # git annex copy --to backup git-annex_coding_in_haskell.ogg copy git-annex_coding_in_haskell.ogg (checking backup...) 12877824 2% 255.11kB/s 00:00 ok You can also `git annex move` files to it, to free up space on your laptop. And then you can `git annex get` files back to your laptop later on, as desired. After you use git-annex to move files around, remember to push, which will broadcast its updated location information. # git push ## take it farther Of course you can create as many checkouts as you desire. If you have a desktop machine too, you can make a checkout there, and use `git remote add` to also let your desktop access the backup repository. You can add remotes for each direct connection between machines you find you need -- so make the laptop have the desktop as a remote, and the desktop have the laptop as a remote, and then on either machine git-annex can access files stored on the other.