Ask SIPB
This week’s column covers the upgrade of Athena clusters to Debathena from Athena 9.4, and details some of the main new features that are now available.
What’s up with all these Debathena machines around campus?
This past summer, IS&T upgraded all the public Athena machines around campus from Athena 9 to Debathena. Debathena, a SIPB project that is now a collaboration with IS&T, is the newest version of Athena. While Debathena packages are available for any current Debian-based distribution, IS&T selected Ubuntu for the public workstations. The current version — Ubuntu 9.04 — allows us to incorporate software as recent as 2009, and it adds some long-requested features to Athena and makes some programs much faster.
How does Debathena improve over Athena 9.4?
Ubuntu 9.04, on which the Debathena cluster deployment is based, is a much more recent operating system, especially compared to Red Hat Enterprise Linux 4, on which Athena 9.4 is based. Support for USB devices and CD-ROMs has been vastly improved — removable devices now appear on your Desktop, with no need to become root or use the attach-usb program. Users are now able to install software packages automatically, even on cluster machines (a feature requested for many years). Debathena workstations in the clusters include many more locally installed applications, such as OpenOffice.org and the GIMP, a powerful photo editor similar to Photoshop. Having these applications installed locally should provide a noticeable speed increase.
My login takes longer on Debathena cluster machines than on Athena 9.4. Are you doing something about that?
Yes. Right now the login process is noticeably slower on public Debathena machines (private machines are unaffected), and we are working to resolve this issue as soon as possible. The primary cause of the slowness is the login chroots or “sandboxes”, which provide users with the ability to install any software they like for the duration of their login session. The ability to do this has been requested many times, and we’re pleased to be able to offer it now. We don’t accept the slowness in the present implementation as a trade-off — we’re trying a number of different solutions to address the speed issue and we hope to have a fix released to the clusters soon. For quickstations, we recently changed the configuration to remove the login chroots and deny root access, which brought login times back down into the 5–10 second range. That lets us keep quickstations quick while we work on a complete solution for both quickstations and the clusters.
Why couldn’t we have just continued using Athena 9.4 in the clusters?
Red Hat Enterprise Linux 4, on which Athena 9.4 is based, is four years old and will stop receiving bugfixes this fall. In another two years, even security fixes will end. Moving to Ubuntu with Debathena delivers newer software with improved features, and because Debathena is designed to be easy to upgrade to new upstream releases — it’s handled eight of them and counting — it ensures we can continue to receive security updates and other important bugfixes, as well as take advantage of the latest features and newest software, for the future. For more information on Debathena, please visit http://debathena.mit.edu.
To ask us a question, send e-mail to sipb@mit.edu. We’ll try to answer you quickly, and we can address your question in our next column. You can also stop by our office in W20-557 or call us at x3-7788 if you need help. Copies of each column and pointers to additional information are posted on our website: http://www.mit.edu/~asksipb/