How to become an SDCC user and work with facility resources.

Quick start for new users:

Additional access methods and facility services:


Home directories - 

Home directories are meant to store small files only. All home directories are restricted by user quotas and the quotas varies as per experiment. 

You can use "quota -s" to check your quota. 

All home directories have a daily backup and snapshot policy. Backups are kept for 30 days and snapshots for 7 days. 

Snapshots can be accessed by navigating to the .snapshots directory. 

Accessing clusters through the gateway

Steps for cluster access using SDCC gateways:

Enable SSH agent forwarding, and use your uploaded SSH key to log into one of the gateways.

Institutional Cluster and Sky Cluster access

From a gateway, SSH to either of the following institutional cluster submit nodes:


The cluster has a debug partition used for debug/interactive sessions

Joining a VO

General information on joining a project's virtual organization (VO).

About VOs

Virtual organizations (VOs) are sets of grid identities, organized in groups, with roles assigned to individuals. Typically, these are groups of people that sit at different physical locations all over the world to achieve a common goal, such as finding QGP or the Higgs boson.

Grid Users

How to start using the grid, and information about virtual organizations and grid certificates (how to get one, renew one, and start using one).

Grid Certificate FAQ

Frequently asked questions regarding grid certificate requests, installation, and use.

While these instructions have been created largely for the benefit of ATLAS VO members, and mainly within the US, members of other VOs may find them useful and should substitute their VO and CA as appropriate.

Certificate and Key Management in macOS

How to import and export certificate-key pairs using the macOS Keychain.

Apple's macOS includes a built-in key and password manager, Keychain, which stores user passwords, user and server certificates, and keys.  Certain applications, including the Safari web browser, use this centralized Keychain for storing and retrieving certificate information in lieu of maintaining their own, separate certificate repositories.  One must use the macOS Keychain in order to add a certificate-key pair to, remove from, or export certificate-key pairs from Safari and other, similar

How to Import a CA Certificate Chain

In order to properly install some certificates, verify certificates from other grid users, and send encrypted messages and verify digital signatures, you may need to import and activate a certificate authority (CA) chain into your browser, email client, or operating system.

This also needs to be done for the CERN CA certificate before using certain CERN applications and web sites.

Troubleshooting X11 Sessions

Diagnosing problems with remote X11 sessions via SSH.

A few of the more common problems with connecting to a remote X11 window session via SSH:

X11 Forwarding

You may not have enabled X11 session forwarding in either your SSH configuration files, or directly in your SSH client application.  On the file system, this can be configured in either, or both, of two configuration files:

  • Your user configuration file: