Introduction to CARC

Last updated November 09, 2023

The information on this page is designed to provide an introductory overview for new CARC users. Links to more detailed information and complete user guides can be found at the end of each section of this page.

For more information about high-performance computing and who we are, see our Computing, Mission, People, and Projects pages.

0.0.1 Introduction to CARC systems

When using CARC systems, you will notice several differences from your desktop or laptop environment:

  • The interface is command-line driven (no graphical user interface)
  • The systems use the CentOS Linux operating system (not macOS or Windows)
  • You submit your programs to a remote batch processing system, or job scheduler, to run them Discovery cluster

Discovery is a high-performance computing cluster, which is a collection of computers and disk arrays that are connected via fast networks. Discovery allows USC researchers to perform computing tasks, like data analyses and simulations, on a larger scale than is possible with a laptop or lab computer. The Discovery cluster is CARC’s public cluster; any CARC user can use Discovery.

The following graphic depicts CARC’s cyberinfrastructure and how different systems interact with one another:

For detailed information on the Discovery cluster, see our Discovery user guides. Endeavour condo cluster

Endeavour is a high-performance computing cluster like Discovery, but Endeavour comprises resources that Condo Cluster Program (CCP) users lease or subscribe to, with each research group’s resources dedicated for their use only. For more information on the CCP, see the Condo Cluster Program pages. For detailed information on the Endeavour cluster, see our Endeavour user guides Storage file systems

All CARC account holders are assigned four directories on four different file systems where they can store files and run programs.

Each file system serves a different purpose:

  • /home1 is a network file system for storing configuration files and personal scripts. Each CARC user has a 100 GB home directory quota.

  • /project is a parallel file system and the primary one to use when running jobs. If requested, a research group will be assigned a subdirectory on /project. Managed by a Principal Investigator, this is where you have access to 5 TB or more of storage space (shared among the project’s members), and where you can collaborate and share files with your research group. If more than 10 TB of storage is needed, it can be purchased in 5 TB increments for $40/TB/year. See the Project and Allocation Management pages for more information.

  • /scratch1 is a parallel file system intended for storing temporary files and running I/O intensive jobs. Each CARC user receives a 10 TB quota for /scratch1.

For detailed information on the different storage systems available, see our Storage File Systems user guide.

0.0.2 Accessing CARC systems

All USC students, staff, and faculty have access to CARC’s systems for their research projects. In order to access CARC’s systems, you must either be the Principal Investigator (PI) of a research project or an authorized member of a PI’s research project.

Access to and use of resources is based on participation in projects. Project setup and resource allocation requests must be made by a project’s PI using the CARC user portal.

For more information on accounts, see our Project and Allocation Management pages.

CARC resources are accessible only through USC’s network, either via direct connection or a USC Virtual Private Network (VPN) with the USC Cisco AnyConnect Secure Mobility Client.

There are several benefits to this:

  • increased security
  • internet access from compute nodes
  • easier connection through the terminal

Duo two-factor authentication is required to access USC VPNs. If you have not already signed up for Duo on your USC NetID account, please visit this page to enroll.

Your USC NetID is the first part of your USC email address (e.g.,’s NetID is ttrojan).

Setup instructions are available on the ITS website for Windows and macOS. Instructions for Linux can be found on our Connecting to a USC VPN page.

Please note that USC ITS provides support for Cisco AnyConnect Secure Mobility Client. If you are experiencing connectivity issues, please contact them here.

Currently, CARC systems do not support the use or storage of sensitive data. If your research work includes sensitive data, including but not limited to HIPAA-, FERPA-, or CUI-regulated data, see our Secure Computing Compliance Overview or contact us at before using our systems.

0.0.3 Resources for deeper learning Workshop classes

Each month, CARC’s Research Facilitation & Applications team offers a number of free workshops designed to introduce users to the computing cluster and its features. The team is frequently developing new workshops, including workshops on useful software and programming languages.

All workshops are approximately two hours in length and are offered several times a year.

For information on the different workshops that CARC’s Research Facilitation & Applications team offers on a rotating basis, see our Workshops page. External tools and resources

If you want to improve your overall understanding of research computing, CARC has compiled a list of external resources that may be helpful for learning about research computing, programming languages, and software used by CARC systems.

For more information, see our External Tools and Resources page.

0.0.4 How to get help Weekly office hours

Every week, the Research Facilitation & Applications team hosts office hours for CARC users to ask questions about anything related to research computing. No appointments are necessary, and all levels of users and questions are welcomed. Currently, all office hours are taking place via Zoom every Tuesday from 2:30-5:00 pm. Office hours are drop-in and do not require registration, but you will need a USC NetID to join the Zoom meeting.

For more information, see our Office Hours and Consultations page. Frequently asked questions

See our extensive Frequently Asked Questions page for answers to common questions about CARC accounts, different cluster resources, and using software on CARC systems. Discourse user forum

CARC uses Discourse, a question-and-answer community forum, to facilitate discussion and knowledge sharing among users. The User Forum is a great resource for discussing CARC-related topics, asking non-urgent technical questions, and sharing ideas. The CARC team monitors the forum for questions, but users are also encouraged to interact with each other. Ticket submission

If you’re experiencing an issue with system resources or your CARC account and you’re unable to find a solution to your problem using the above resources, please submit a help ticket to the CARC team.