View source for SSH server upgrade to Ubuntu 14.04

The ssh-linux servers <tt>ssh-linux4</tt>, <tt>ssh-linux5</tt>, <tt>ssh-linux7</tt>, and <tt>ssh-linux8</tt>, which are running Debian 6, are scheduled to be replaced.

==Notable changes==

* The new server pool is called <tt>ssh-ubuntu.ece.ubc.ca</tt>.
* Operating system is Ubuntu 14.04 rather than Debian 6.
* Expanded list of installed software packages.  (If any [http://packages.ubuntu.com/trusty/ Ubuntu package] that you want to use is not installed, please [[How To Report A Problem|file a request]].)
* MATLAB version is R2014a; versions R2008b and R2013b have been dropped.
* Hosted on virtual servers in the University Data Centre for better performance and reliability.
* The Debian Subversion client (version 1.6.12) cannot access repositories created with the Subversion client on Ubuntu (version 1.8.8).

==Upgrade plan==

# As of now, you can start using the new servers by using <tt>ssh-ubuntu.ece.ubc.ca</tt> as the server hostname (instead of <tt>ssh-linux.ece.ubc.ca</tt> or <tt>ssh.ece.ubc.ca</tt>).
# As part of the [[ECE Storage Migration (Aug 15 and Aug 22, 2015)|ECE Storage Migration]], all <tt>ssh-linux</tt> servers (both Debian and Ubuntu) will be rebooted the night of August 22. After the reboot, <tt>ssh-linux</tt> will point to the new Ubuntu servers.  You will still be able to connect to <tt>ssh-linux4</tt>, <tt>ssh-linux5</tt>, <tt>ssh-linux7</tt>, or <tt>ssh-linux8</tt> explicitly.
# In a few months, we will shut down the old servers completely.