Help Home

CSE Home

Instructional Cluster

This cluster is a set of 8 machines that can be used by students that need root access to complete coursework. Home directories are not shared to these machines and they have to be accessed from IT or CS machines. A networked power distribution unit and console manager is provided in lieu of physical access. Users can debug issues via the serial console and powercycle the machine this way.

The machines are 2.4 GHz Pentium 4 machines with 1 Gigabyte of memory each. 73GB of hard disk space is provided, at least 65GB is free for use. The machines run Ubuntu Linux.

Access to the machines will be coordinated through faculty members who verify that the project requires root access to be completed. A faculty member should contact Systems Staff and indicate which users should be allowed access to the cluster. The faculty member must assign groups to machines as there are only 8 machines available, please specify the groups when making the request. These users will need to come down to Operator and sign a document authorizing use of the machines to recieve the password for that machine.

To use the machines, just login to the name of the machine that has been assigned along with the username which should be the same name as the machine. Then, to gain root access just run 'sudo su'. Users may be added to the machine only if they are part of the group authorized to use the machine and are affiliated with the University. Add the user to /etc/group in the 'admin' group.

Users must not remove any information in /root/.ssh/authorized_keys2. This allows Systems Staff to access the machines as necessary.

Additional information on Ubuntu Linux can be found at Ubuntu Linux.

To access the console server, just ssh to the port with the port username indicated below to icluster-cm.itlabs.umn.edu. You must ssh to this machine from an ITLabs or CS machine. Use the password assigned to gain access and the port below to access the machine. To specify an alternate port for ssh use the '-p' option. Ctrl-Z brings up a menu to exit or send a break. A break can be sent to bring up the Alt-SysRq menu under linux which can be used to get debugging information. ~break and ~. can also be used to send a break and close the port respectively. GRUB and the BIOS are configured to display via the serial port, too. If you press a key when "Press any key to continue" starts displaying on the screen the GRUB menu will appear.

To forcefully reboot the machine just go to the power distribution unit website and login with the port username listed below. Then, choose 'Reboot Immediate' for a Control Action and click on the box next to the outlet to reboot then click "Next". Then, on the next page click "Apply". At this point the machine will be forcefully rebooted. You can watch the machine boot up on the serial console via the console server.