Making backups
==============

As well as helping to keep track of different versions of a project, version
control systems are hugely useful for keeping backups of your code with
minimal hassle.

Making a copy of your repository is as simple as moving to the location where
the backup will be, and then using the :command:`git clone` command.

.. code-block:: bash

    $ cd /Volumes/USB_DRIVE
    $ git clone ~/my_network_model

.. code-block:: bash

    $ cd ~/Dropbox
    $ git clone ~/my_network_model

.. code-block:: bash

    $ ssh cluster.example.edu
    (cluster)$ git clone ssh://my_laptop.example.edu/my_network_model

You can then keep the backup in-sync with the main repository by either using
:command:`git pull` in the backup location, or using :command:`git push` in
your working directory:

.. code-block:: bash

    $ cd ~/my_network_model
    $ git push /Volumes/USB_DRIVE/my_network_model master
    Everything up-to-date

Why is this better than just copying the files? Because you no longer have to worry about versions or about over-writing
your changes. i.e., no more:

    *"Now, is the version on my USB key newer than my local version? Did I change any files on my laptop?"*

or:

.. figure:: http://www.phdcomics.com/comics/archive/phd052810s.gif
   :alt: Cartoon from "Piled Higher and Deeper" by Jorge Cham
   :target: http://www.phdcomics.com/comics.php?f=1323