Improvements over Athena 9

While Athena 9 focused on compatibility with previous versions and providing a homogenous environment across different hardware platforms, Debathena was designed with modularity, standards, and user experience in mind. Debathena introduces many new features, while still retaining compatibility with Athena 9 wherever possible. Below are some of the more prominent improvements Debathena has made:

• Based on Ubuntu: The version of Debathena deployed in the public clusters is based on Ubuntu, the leading desktop Linux distribution.
• Modular: While Athena 9 workstations require that you install the entire Athena environment for things to work correctly, Debathena allows a user to select any desired level of Athena compatibility. Debathena has been carefully designed so that each package follows Debian policy as closely as possible and can be uninstalled cleanly; thus you can change the level of Athena compatibility that you want on a machine.
• Improved laptop experience: Due to the modularity described above, laptop users can pick and choose which components to install, and still make use of portions of the Athena environment without a constant network connection.
• /mit automounter: Debathena uses an automounter for /mit, rather than having the attach program manage symlinks there. This means that you can access lockers by simply using paths of the form /mit/locker, without needing to remember to attach the locker.
• Distribution-supplied software: Debathena uses the distribution’s software unmodified whenever possible, which means Athena machines can take upstream updates immediately. In particular, installations of Emacs, Evolution, Gaim, TeX/LaTeX, and the GNOME and Gtk libraries now come directly from the distribution.
• Locally-installed software: In addition to using stock versions of software, we’re also installing it locally wherever possible. Many popular third-party software packages currently in AFS will be available locally, resulting in shorter startup times and improved performance.
• Better removable device handling: CDs, DVDs, and USB drives should now automatically appear on your desktop, allowing you to easily access the files on them.
• Improved compatibility: On Debathena, /usr/athena and /bin/athena paths are symlinks provided only for compatibility; they are not in the user’s PATH or LD_LIBRARY_PATH. This means that software designed to run on a Debathena machine but not depending on Debathena-specific software will work outside the Athena environment.
• Improved user management: While Athena workstations manage user information by adding users to the /etc/passwd file when they log in, on Debathena, user information is retrieved directly from Hesiod via the nsswitch library. This has the advantage that information like the user’s shell updates immediately upon a change in Hesiod, rather than waiting for the user to logout. We wrote nss_nonlocal in order to avoid any security problems related to namespace conflicts between local and Athena-wide users.
• attach is no longer setuid root: The attach program on Debathena runs setgid attach, not setuid root. While lockers can be accessed via the /mit automounter, the attach program is still useful for the add shell function and Zephyr subscription functionality.
• Network configurations and services are managed by the OS: Athena 9 configured network settings and services via two custom features: /etc/athena/rc.conf and the mkserv program. Debathena does away with these, and network settings and services such as sshd, httpd, etc. are managed by the operating system, allowing you to use the standard graphical tools provided by Ubuntu and Debian.