Getting Started

Logging onto Tahoma

To log on Tahoma remotely, use:

ssh –X your_userid@tahoma.emsl.pnnl.gov

The -X option allows remote users to access X Windows functionality across the internet.

SSH certificate authority

MSC generates SSH certificates for the primary login nodes using an SSH certificate authority. Most recent ssh clients support these certificates. You can add the following entry to the known_hosts file to make use of this certificate.:

@cert-authority *.emsl.pnnl.gov ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBDK+36vMP1V80ZKgkI8+l6xn4plUmL2Qz5L6jfQ4zO0/gYZzqFkcvNmlnoGks4393F/fqSi+88Yrnoi4An/ouvM=

Key fingerprints

MSC may occasionally update the host keys on the major systems. Check here to confirm the current fingerprint for Tahoma. If you see an alert about that indicates the fingerprints are different and they don’t match the following, contact support at mscf-consulting@emsl.pnl.gov

256 SHA256:nVM3LBAOX8yGjtSu6yshArRinOOHgIvAvPjIpGZl0aE no comment (ED25519)
256 SHA256:NL0GTmT34SFOlsZKOdRLkt6tYtmk0Pk2POJyXWIgqV0 no comment (ECDSA)
2048 SHA256:hCGPIDVTCOEnpfBGMC42ODxuNJcqd0oxGjWL/TDrPI8 no comment (RSA)

Running Jobs on Tahoma

Tahoma is a batch scheduled environment managed by Slurm. For commonly used software such as:

  • NWChem

  • VASP

  • ADF

  • GAMESS

  • MOLPRO

  • etc.

We have pre-formed submission scripts that either interactively query you for the required input fields or take a prescribed set of arguments. These scripts then build the submission script and submit it for you.

To list the available submit scripts type:

ls /home/scicons/tahoma/bin/submit*

These scripts are outlined further in Available Science Applications.

Most of these scripts accept a -h or --help as an argument to give a description of how to use them. When using the preformed submit scripts, please be sure to run them from your /tahoma project directory. This is so that output files land in the BeeGFS file system which has much higher bandwidth and lower latency than the /home file system. It is also a good idea to have the input files (if needed) in the /tahoma file system.

Running jobs are subject to the limits set within our Job Policy.

Project Account Names on Tahoma

All of the above pre-formed scripts and when you build your own you need to specify which project account is to be used. To see which project accounts you are permitted to run under, type:

gbalance

This will produce a list of the projects you may run under as well as the node hours used and remaining in the project. In the non-header lines of the output, the characters up to the first blank are the project name. If you are building your own submission scripts you will need to define the project in your scheduler directives:

#SLURM --account 'project'

Writing a Batch Script

If you are creating your own submission script, you submit them with the sbatch command:

sbatch 'my_submission_script'

The scheduler will return the SLURM job ID or some error message if your account is incorrect or the scheduler is not accepting jobs. When submitting jobs, please run them from your /dtemp project directory.

More information is available at Job Scripts.