HMC Mathematics Computing Weblog

The department has been able to negotiate a deal with CIS to replace the machines in our Scientific Computing Lab with new workstations. (We traded our share of an IBM grant for money to use for other systems.)

We will be replacing the current mix of machines in the lab with twelve new Dell OptiPlex 960n systems, each with a 3 GHz Core 2 Duo processor, 4 GB of RAM, an ATI Radeon HD 3450 video card, and a 22" widescreen LCD monitor. These machines will run the latest release of the CentOS Linux distribution (currently 5.3).

We expect to have the machines in hand in mid-June, with deployment to follow soon after.

We will be rebooting the department's main file server, gytha, to apply some security updates and improve the stability of our web server.

The reboot will happen at 5:00 PM on Wednesday, June 3, 2009. The outage may last as long as two hours.

Affected Services/Systems

Rebooting gytha will affect almost all services provided by the department, including mail, logins on department Macs and Linux systems, and personal/faculty web pages, as gytha provides all home directories, and those services depend on access to your home directories.

Windows machines and other machines that use CIS servers will not be affected unless you're mounting drives from our servers as well.

Core web pages (those without a ~ in the URL) will not be affected.

Duration and After Effects

The reboot could take as little as 15 minutes or as long as two hours, depending on how many file systems need to be checked; as the machine has been running continuously for 216 days (at this writing), a longer outage is likely.

After the server reboot, desktop Macs running Mac OS X 10.4 (Tiger) will need to be rebooted, as their NFS software does not handle reboots gracefully. Some Linux servers and workstations may also require attention.

What You Should Do

Log out of your account before 5:00 PM on Wednesday, 2009 June 5. I will take down mail services (including incoming and outgoing mail and IMAP and POP services) prior to the reboot, so you don't need to worry about quitting mail clients on home machines or laptops, but you will not be able to send mail through our mail server until the file server is back up and mail services have been restarted.