The secure shell (SSH) server on hpc-portal1.hpc.uark.edu does not accept passwords as an authentication method. Instead, SSH key files are used for access. A public SSH key file is stored in your account on Pinnacle. You must supply a matching private key (pinnacle.key) file as a parameter to the ssh command on the client to log in.

ssh -i pinnacle.key ffinfinn@hpc-portal1.hpc.uark.edu

Both private and public keys are generated and configured automatically on Pinnacle via the web portal. To enable SSH password-less access:

• Log into the web portal at: https://hpc-portal1.hpc.uark.edu
• In the top menu go to Clusters → SSH keys

• Click on Create New SSH Key or Use Existing SSH Key if available. Both buttons will redirect your browser to a file manager window allowing you to download your private SSH key pinnacle.key file to your client device.

• Click on the checkbox next to the pinnacle.key file and press the

  • Download button at the top. The file will likely be saved to your Downloads directory. - Before the file can be used for SSH, the file permissions must be updated to read-only for owner (mode 400) on macOS and Linux: <code> cd Downloads/ chmod 400 pinnacle.key </code> - Use the new key to SSH into Pinnacle: <code> ssh -i pinnacle.key ffinfinn@hpc-portal1.hpc.uark.edu PLEASE CITE US in your publications * This research is supported by the Arkansas High Performance Computing Center which is funded through multiple National Science Foundation grants and the Arkansas Economic Development Commission. Login nodes are for file operations and job submission. All login nodes run a different kernel than compute nodes, so: - Don't compile on login nodes. Resulting code won't work on compute nodes. - Don't run R or Python on login nodes. For a shared cloud compute node: srun -N1 -n1 -c1 -p cloud72 -q cloud -t 72:00:00 –pty /bin/bash Last login: Fri Apr 10 10:14:51 2026 from 167.224.131.232 Pinnacle file system usage for ffinfinn Filesystem Usage/Quota Files/Quota /scrfs 4.059T/10TB 21798831/10.0 million /scr1 16k/ 1TB 4/ 2.5 million /scr2 96k/ 1TB 24/ 2.5 million pinnacle-l11:ffinfinn:$ </code>