Frequently Asked Questions

1. How do I find out which compute platforms and software are available at GACRC?

A list of GACRC systems, including a brief description of the compute platforms, is available at the Systems page.

Applications and software available on GACRC machines are grouped by category. For an alphabetical list of all software installed please refer to the Software page. You can sort by Category or by software Name.

2. How do I apply for accounts on GACRC machines?

User accounts are created as part of a "lab group" which has been registered by a Principal Investigator (PI), i.e. a UGA faculty. Once the group is registered, the PI will receive an email stating that he/she can request individual accounts for members of his/her group. For more information, please see http://dev.gacrc.uga.edu/accounts

3. How do I connect to a GACRC machine?

Users can access GACRC machines using secure shell (ssh) from their local machines either on-campus or off-campus. To connect via ssh, you must have an ssh software on your local machine and a connection to the UGA campus network. ssh software is included in recent releases of Unix based operating systems (including Linux and Mac OSX). An SSH Secure Shell Utility is available for Windows on the UGA Sitesoft page (you will need to enter your UGA myID and password to download the software). Note that connection via telnet is not allowed .

For more detailed information on how to connect to a specific GACRC machine, please see the Connecting page.

4. How do I copy files to/from a GACRC machine?

Users can transfer files between their local machines and GACRC machines using FTP with explicit SSL encryption, a secure copy (scp), or an SSH secure File Transfer software (SSH file transfer). To transfer files using scp (or SSH file transfer) you must have scp (or SSH) on your local machine and a connection to the UGA campus network. An scp software is included in recent releases of Unix based operating systems (including Linux and Mac OS X). An SSH Secure File Transfer Utility is available for Windows on the UGA Sitesoft page (you will need to enter your UGA myID and password to download the software).

Users are encouraged to use FTP with explicit SSL encryption for file transfer to zcluster. Two file transfer software that support FTP with explicit SSL encryption are the open source software FileZilla (available for Windows, Mac OS X, and Linux) and WinSCP (available for Windows machines).

For more detailed information on how to copy files to/from a specific GACRC machine, please see the Transferring Files page.

5. How do I print files that are on a GACRC machine?

Files on any GACRC machine cannot be directly printed on your local printer. Please transfer the files from the GACRC machine to your local machine (see question above) and print them from your local machine.

6. How do I run jobs on a GACRC machine?

Jobs should not be run on the login node of GACRC machines. The Linux cluster (zcluster) uses a variant of the Sun Grid Engine queueing system, which should be used for both interactive and batch jobs. For more information, please see the Running Jobs on zcluster page.

7. How do I change my default shell on a given machine?

When you login to an GACRC machine, the environment on your terminal and the commands that you type at the prompt are defined/interpreted by a program called shell. Examples of shell are bash, csh, ksh, tcsh. The syntax for setting environment variables and some of the functionality of your keyboard depend on the shell that you are running. For example, with bash and tcsh it is straightforward to use up arrows to recover previous commands. All users have a default shell defined at account creation time. Users can change their default shell by typing chsh at the command prompt. Note that this command needs to the run on the login node and on the interactive nodes (if you want the shell changed on them as well).

8. Can I use text files (programs, scripts, etc) created on a Windows machine on the GACRC Unix/Linux machines?

Text (ascii) files created on Windows machines might have Windows newlines that are not interpreted correctly by a Unix/Linux system. However, you can convert a Windows text file to the Unix/Linux format with the dos2unix command available on the GACRC altix and rcluster. The syntax is

dos2unix filename

where filename is the name of the ascii file (such as program.c, program.f, run.sh, input.txt, etc) created on a Windows machine.

9. Can I use text files (programs, scripts, etc) created on a Mac on the GACRC Unix/Linux machines?

Text (ascii) files created on computers running Mac OS might have Mac newlines that are not interpreted correctly by a Unix/Linux system. However, you can convert a Mac text file to the Unix/Linux format with the mac2unix command available on the GACRC altix and rcluster. The syntax is:

mac2unix filename

where filename is the name of the ascii file (such as program.c, program.f, run.sh, input.txt, etc) created on a machine with Mac OS.

10. How do I forward X Window applications running on GACRC machines to my Windows desktop?

A number of software installed on GACRC machines have X Window (GUI) front ends. Examples of such applications are Mathematica, Maple, SAS, some text editors and debuggers, etc. In order to export such X Window applications to your Windows desktop, your desktop needs to have an X Window client (or server) running on it. A free X Window server for Microsoft Windows (XP/2008/Windows7) is Xming. You can download it from Sourceforge and make a default installation. You will need to install the Xming server and the Xming-fonts package. During the installation of Xming, you might want to select the option to create a desktop icon for Xming. When the installation of these two packages is complete, double click on the Xming icon to start the X Window server (a capital X will appear on your task bar). Now you need to configure your SSH client to allow tunneling of X11 connections. For example, if you use the SSH client provided at the UGA Sitesoft page you need to open the SSH client, then click on

Edit -> Settings -> Tunneling (under Profile Settings)

and check the box for "Tunnel X11 connections", and then save the settings. Once that is done, you can SSH into your GACRC account (zcluster, stats) and run X Window applications. The application should appear on your local Windows desktop. Each time you logout and log back into your Windows desktop, you might need to start the Xming Server manually before using SSH to connect to your GACRC accounts.

11. How do I acknowledge the GACRC in my publication?

A sample acknowledgment statement is provided at http://dev.gacrc.uga.edu/about/acknowledgment-statement