Notes on UTCS Deployment of Ubuntu 20.04 (Focal)

Publicly available desktops running focal currently include: All of the philosopher64 group

hosts in the boardgames64 group are now funning focal

A relatively up-to-date list of all desktops running focal can be found by running cshosts focaldesktops on any CS linux host

Changes from Ubuntu 18.04 (Bionic):

  • /usr/local is no longer a symlink to /lusr, and the default path now includes /usr/local/{sbin,bin} and /lusr/{sbin,bin}.  Nonetheless, we know this will impact some workflows.  If you encounter issues that you believe are due to this change, please let us know.
  • Home directories are now mounted NFS 4.1 by default (Bionic was NFS 3).
  • /lusr and /share are now mounted NFS 4.1 by default (Bionic was NFS 3).
  • While Ubuntu 20.04 installs python 3 (3.8.10) by default, we have installed Python 2 (2.7.18) as well, but please note that a lot of python2 modules are no longer provided as Ubuntu packages (mysqlclient/MySQLdb for instance).  We strongly encourage you to update your code to use Python 3 and/or verify that your Python 2 programs still work.  Let us know if you encounter missing Python 2 modules.  
  • /usr/bin/python points to Python 2.  This causes issues with projects that expect /usr/bin/python to point to Python 3 (ROS Noetic, for instance).  Python recommends the use of virtual environments to ensure that "python" uses the correct version.  For more information, see https://peps.python.org/pep-0394/

Known Issues:

  • NFS4 expects file names to be encoded in UTF-8.  If a file or directory name was created with a non-UTF-8 encoding (which is quite unusual in our experience), NFS4 may not handle it correctly.  In most cases, the file name simply won't be displayed correctly, but in very rare circumstances it is impossible to refer to the file correctly, preventing the file from being the argument of a command (even with a wildcard or recursively), making it impossible to move or delete the file.  A local workaround will be provided shortly.
  • Chromium (web browser) is currently not available.  Ubuntu has started providing chromium as a Snap package only, and Snap packages do not work with our NFS environment.  This may change in the future.  Note that Google Chrome browser (Google's branded build of Chromium) is still installed
  • Alpine is currently not available.  Alpine requires custom patching to work in an NFS environment.  This may change in the future.