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.