• Getting Started
  • Introduction
  • Your User Account
  • Logging On and Off
• Policies
  • Rebooting Workstations
  • Running Background Jobs
  • Game Playing
  • Screen Locking
• Operating System / Shells
• System News
• Storage
  • Storage Variables
  • Disk Quota Limits
• Programming Environment
  • Development Suites
  • Scripting Languages
• Modules
• Duckering Access Lab
• More Information

The Arctic Region Supercomputing Center (ARSC) maintains a number of workstations running Red Hat Enterprise Linux. As one component of ARSC's computational environment, these machines are available to ARSC Academic users as workstations.

To obtain an account for the Linux workstations, you must request resources from ARSC. Workstation accounts are subject to the same policies and restrictions as other ARSC accounts.

Security is a major responsibility assumed by applying for and accepting your ARSC account. If someone else, either with or without your compliance, gains access to ARSC computational resources via your username and passcode, you may be held responsible for their actions.

All ARSC users will receive a Username, SecurID Card, and PIN number for their SecurID Card when they obtain an account.

Once issued an account, there are several ways to connect. One approach is to sit down at a workstation in one of the ARSC access labs, and log directly onto the desktop. To do this, move the mouse around to awaken the screen-saver. It will present you with a dialog box:

Respond as follows:

Please read our Academic Authentication Procedures for detailed information about logging onto other ARSC hosts.

To disconnect, use the mouse to select System -> Log Out username ... from the menu bar.

Pressing the reset button or power switch on a Linux workstation is considered an abuse of the system as other users may be accessing the system remotely. Any time power is lost to a workstation, the filesystem may be damaged. If there is a problem with a system, check with the lab assistant, or contact User Support.

The primary purpose of the Linux workstations is to provide interactive console use and data processing services. Background processes are permitted on these systems, however long background jobs without checkpointing are vulnerable to data loss, and urgent system administration tasks may require termination of background jobs with little or no notice.

Playing computer games on ARSC systems is considered an inappropriate use of ARSC resources.

ARSC requires users to lock their screens during all absences from a workstation. This is a necessary precaution to prevent anybody else with physical access to the machine from using your account inappropriately.

To manually lock the screen, select System -> Lock Screen .

No locking for over 15 minutes! Screen locking is intended for short absences, not to allow a user to monopolize a system. Please help maintain an atmosphere of mutual support and cooperation by leaving a terminal for no more than 15 minutes. If screen locking is abused, let us know, and we will address the issue with the user.

The following shells are available on the Linux workstations:

• sh (Bourne Shell)
• ksh (Korn Shell) default
• bash (Bourne-Again Shell)
• csh (C Shell)
• tcsh (Turbo C Shell)

If you would like to have your login shell changed, please contact User Support

System news is available via the "news" command  when logged onto a Linux workstation or on the web:

• Access Systems News Items

On all ARSC systems, several environment variables point to elements of the storage environment and are defined for users. Please use these environment variables:

* Requests for increased quotas should be sent to User Support.

Here are more details, subject to change, on the Linux workstation storage environment.

• $HOME directories are intended primarily for basic account infomation (e.g. dot files).
• $SCRATCH is intended for job I/O or any workstation activity that would benefit from increased I/O performance. This includes compiles, input files, output files, etc.
• The $CENTER filesystem is not currently being purged on a daily basis, however it may be enabled at a future date.   Data residing in $CENTER for inactive accounts may be purged without warning.
• Long-term backed up storage is only available in your $ARCHIVE directory. $ARCHIVE is an NFS-mounted filesystem from ARSC's Sun Storage Server (bigdipper). Files will be temporarily unavailable when bigdipper is taken down for maintenance and I/O performance in this directory will be slower than $SCRATCH. Compilations in $ARCHIVE are not recommended.

See Storage Management for more information on storage policies at ARSC.

All home directories have a default disk quota limit of 4 GB. Requests for larger quotas should be sent to User Support . Using the command quota -v allows you to see your disk quota and current use for your home directory. The output from this command will look similar to the following:

Quotas are reported in Kilobytes. Should you need additional space, please contact User Support .

If you would like to be informed about your current disk space usage upon log in, you can add the command "quota -v" to the file ".login" in the top level of your home directory if you are using C shell, or ".profile" if you using Bourne or Korn shell.

Development Suites

* To use the Portland Group compilers and tools, you must first load the "pgi" module. Please refer to the Modules section of this document for more information.

In addition to the Portland Group and GNU compilers and analysis tools, ARSC's Linux workstations include many popular scripting languages, including Perl, Python, and Ruby.

Linux workstations have the "modules" package installed. This tool allows a user to quickly and easily switch between different versions of a package (e.g. compilers). The module package sets common environment variables used by applications such as PATH, LD_LIBRARY_PATH, etc.

Before the modules package can be used, you must first source the modules "init" file corresponding to the shell you are using. For example, if your shell is bash, you would need to type:

       source /usr/local/pkg/modules/init/bash

Once the appropriate "init" file has been sourced, you can use the modules package with the following commands:

Located in the University of Alaska Fairbanks Duckering Building, room 234, the Duckering Access Laboratory provides computational resources to its users in a convenient location on lower campus. Read the Access Lab Policy for details on gaining access to this lab.

Linux Man Pages When using a Linux shell interface, you can access the traditional Linux manuals by typing "man" followed by a command name (for example, " man man or " man ls ).

Training Classes ARSC offers courses on subjects of interest to users of HPC and Access systems.

Consultants You may contact User Support via email or by phone.