You can log in to NERSC systems using SSH (Secure Shell) with the following command from any UNIX, Linux, FreeBSD, etc. command shell or terminal:
ssh -l username cori.nersc.gov
ssh -l username denovo.nersc.gov
There are several SSH-capable clients available for Windows, Mac, and UNIX/Linux machines. NERSC does not support or recommend any particular client.
The login nodes are situated behind a load balancer, so you may be connected to different login nodes at different times. If you make use of a tool like screen or tmux, note which login node your sessions are on, and after initially logging on to Cori you can ssh to a specific login node.
Computational systems hosted at NERSC use the Slurm batch scheduler system. Documentation and instructions for using Slurm can be found here.
A subset of nodes on Cori, the flagship supercomputer at NERSC, are reserved for exclusive use by JGI by using JGI-specific "quality of service" (QOS) submissions. Full functionality of Cori is also available to JGI users such as the Burst Buffer, Shifter, and more.
The Denovo system is exclusively available to JGI users. It is scheduled for retirement in July 2019.
Although we provide documentation on usage of Denovo we highly recommend that most of your work be done on Cori genepool (the QOS dedicated for JGI workloads) or Cori ExVivo.