Frequently Asked Questions

Table of contents

Access & Authentication

How do I get an CAG account?

All accounts must be requested through the CAG System Adminstrator.

How do I change my CAG password?

Log into the server you have been given access and run:

passwd

I forgot my CAG password. What do I do?

Contact the CAG SysAdmin to request a password reset.

I can’t connect via SSH from outside LBNL.

LBNL IT’s Firewall can be aggressive if it sees too many connections from unknown IP addresses. Follow the instructions found on LBL’s Blocked Access to the Lab Network page.

Computing Resources

What servers do we have access to?

For a full list of available systems, check the resources page.

Remote GUI Access

XRDP vs VNC — which should I use?

  • XRDP gives you a full remote desktop session and works well on most systems
  • VNC is lighter-weight and gives you more control over individual sessions
  • XRDP is generally more user-friendly; VNC gives you more flexibility

Do I need to keep the SSH tunnel open?

Yes. The SSH tunnel encrypts the remote GUI traffic. If you close it, your GUI connection drops. If your internet drops, reconnect via SSH tunnel first, then reconnect your GUI client.

Software & Environments

Can I install software on our servers?

Generally, you can install tools in your home directory without sudo privileges. For system-wide installations, contact the CAG SysAdmin.

Troubleshooting

My session keeps timing out

  • Add ServerAliveInterval 60 and ServerAliveCountMax 3 to your ~/.ssh/config
  • Use an SSH multiplexed connection: ssh -M -S ~/.ssh/master-%r@%h:%p SERVER

Disk space is full

Run du -sh ~/* \| sort -hr | head -20 to find large directories. Clean up old environments, downloads, and temporary files.

Still stuck? Contact our administrators for more information.