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+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.
+
+## set up the repository, and make a checkout
+
+In this tutorial, I'll set up a centralized repository hosted on
+GitHub. I've created a repository for technical talk videos, which you can
+fork, 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
+
+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
+
+Tell git-annex to use the repository, and describe where this clone is
+located:
+
+	# git annex init 'my laptop'
+	init my laptop ok
+
+## 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'
+
+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.
+* All of the above!
+
+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 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.)
+
+	# 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.
+
+## take it farther
+
+Of course you can create as many checkouts as you desire. If you have a
+desktop matchine 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.