Introduction For New Users
Finding Help and News
Reaching Us: Consultants On Call
Consultants are on duty Monday through Friday, between 8 AM - 5 PM Alaska time. Contact User Support for more information.
MOTD or Message Of The Day
The MOTD appears each time a user logs onto a machine. The MOTD is updated frequently to keep users informed. Review the MOTD at any time by entering the following command at the shell prompt:
On any ARSC machine, type news | more to read all unread news items, one screen at a time.
Reading a news item marks it as read , therefore running this command clears the list of unread items presented upon each log on. Thus, only new and updated items will be presented during the user's next login.
To read any particular item, type news item | more , where item is the name of the news item to be read. When running jobs on an ARSC system, it is a good idea to check the upcoming and most recent downtimes for each system with news downtime | more .
System News on the Web
System news and scheduled maintenance is also available online.
ARSC HPC Users' Newsletter
Offering current information for ARSC users and the wider HPC community, this bi-weekly newsletter is available via email subscription and online.
ARSC provides one-on-one training upon request, formal seminars, and short-courses throughout the year. See our Training and Classes list for upcoming scheduled classes.
Connecting and Logging On
University of Alaska Passwords
Users may use their University of Alaska (UA) password to access ARSC systems. This password is used to access UA email, etc.
This password can be reset using the ELMO page
ARSC supports remote access to ARSC system using ssh, scp and sftp clients. Linux and Mac systems generally come preconfigured with these software packages. Windows users may need to install additional software in order to support ssh based connections. See the Academic User Authentication guide for recommended client software.
Connecting with SSH and using X Windows on Linux and Mac Systems
If you wish to run X Windows Applications, we recommend connecting with an ssh client. To avoid problems while running X Windows Applications over ssh, be sure to connect using the "-XY" option. For example:
ssh -XY pacman.arsc.edu
If system compatibility issues prevent a connection using ssh, alternate connection options are available. Please contact User Support for further information and assistance with remote connectivity to ARSC systems.
Using X Windows and MS Windows Operating Systems
If you wish to use X Window based applications from a system running Microsoft Windows, you must have an X11 client as well as an ssh client. There are several X11 clients available for Windows including the Exceed X-Server, XMing, and the freely available Cygwin X11 server. For instructions on configuring and setting up X Windows using Cygwin, please view this document .
Checking and Forwarding Email
Your ARSC systems account forwards system email to the email address that you provided when your account was created. After initial account creation, you may alter the ~/.forward for your account to change the email address to which system messages are sent.
Getting Started on ARSC Systems
See ARSC's current line-up of HPC and other user systems .
Getting Started Guides
Find your system in the list of Getting Started Guides .
Operating Systems at ARSC
All ARSC HPC systems run variants of the Unix operating system.
Running a Program
The current working directory is not included in the user's default PATH. Therefore, to run a program interactively (even if the executable is in the current default directory), the path to the executable filename must be specified. For example, to run a program titled a.out from the current directory, type:
As an aid to new (and experienced!) users, ARSC maintains a repository of sample codes on each major HPC system.
To submit a batch job on any of the HPC systems, you will create a script containing formatted information regarding the size and duration of the job to be run, and the commands needed to execute the program. See the "Getting Started" pages for your system for instructions and examples.
Storage is an important, finite resource. Please maintain an understanding of the various storage mechanisms available, and use the storage systems efficiently. For further details, see the Storage Management document.
Limits, Restrictions, and Miscellaneous
Managing Your Allocation of CPU Hours
See Resource Accounting page.
Quotas: Monitoring Disk Space
On the systems implementing quotas, a user may view their disk space allocation by using the quota -v or show_storage commands (see each machine's getting started guide for the appropriate quota query.)
For details on ARSC's implementation of quotas, please see the Storage Management documentation.
Disk Usage Monitoring
The du command displays the total storage used within a directory and all of its subdirectories.
Useful options include -k , which displays the storage in kilobytes instead of blocks (1 block = 512 bytes) and -s , which provides a brief summary listing.
Filesystem Purging Policies
View Storage Management for a summary of filesystems and the frequency of purging old and unused files.
Home Directory Permissions
You must be careful not to set write permissions on your home directory. Please see the policy on home directory permissions for more information.
ARSC users must abide by certain policies affecting overall system security and the use of shared resources. The following documents are required reading :
- General User Policies (which includes the security policies).
System Maintenance and Downtime
ARSC supercomputing systems are usually taken offline for preventive maintenance on Wednesday evenings from 6:00 PM - 10:00 PM Alaska local time. Workstation systems are scheduled to be taken offline as needed with as little impact on users as possible.
We notify users as early as possible via the "message of the day" ( MOTD ) if we are scheduling preventive maintenance downtime. Type news downtime | more at the shell prompt on any system to view recent and planned downtimes for that individual system.
Please contact User Support if you encounter any problems or have any questions during your computing experience with the Arctic Region Supercomputing Center.