If the glossary is missing a term you don’t understand, please contact Yidan Tang.


This is your home directory (alias: ~). You should not put data here. This directory is intended for configuration scripts, job scripts, etc. You can always get here by cd ~ or equivalently cd $HOME.

absolute path#

The full path to a file. Absolute paths start with / followed by the entire path to the file. For example, /storage1/fs1/rvmartin/Active/wustlkey/project1/file1.txt is an absolute path. If you were in the directory /storage1/fs1/rvmartin/Active/wustlkey the relative path to the same file would be project1/file1.txt.

batch job#

A bash script which executes things. The job runs on the system and it’s output is logged, but there is no interactive terminal. Batch jobs are used for computational work (e.g., a GEOS-Chem simulation). You should use batch jobs (rather than interactive jobs) whenever possible (it will save you time in the long-run).


The HPC cluster (physically, the group of servers which we run computations on).


Your job will run on an exec node inside a container. A container is a bundle of software. Our group has several containers with software frequently used by our group, like compilers, NCO (NetCDF operators), and all the software that GEOS-Chem/GCHP needs. These containers are the mechanism that allows RIS to distribute a variety of software to different research groups on Compute1. Compute1 is based on Docker containers. You can build these yourself and there is plently of documentation online.

environment variables#

These are variables (in your terminal) which some programs (e.g., LSF) use to configure various settings.

exec nodes#

Your jobs run on exec nodes. Both interactive jobs, and batch jobs are run on exec nodes.


This is the data repository for all GEOS-Chem data (e.g., metfields, HEMCO, etc.). In your job, this directory is mounted to /ExtData. On Storage1 this directory is located at /storage1/fs1/rvmartin/Active/GEOS-Chem-shared/ExtData. Note ExtData is an offical data repository for GEOS-Chem, so it is read-only. For custom emissions, you will have to put them elsewhere (the shared directory would be a good place)

head node#

When you SSH into Compute1 you will land on one of the head nodes. Head nodes are essentially the login servers for Compute1. These head nodes have names like compute1-client-3. When you’re on a head node you can interact with LSF to submit jobs, kills jobs, see how much acticity is in each queue, etc., and you can navigate around the filesystem and modify files. You should not run CPU-intensive things on a head node.


Same as a node. It is usually used to refer to a specific node, computer, or server. For example, the term localhost is commonly used to refer to laptop/computer at your fingertips.

interactive job#

A job in which you will be connected to a terminal on an exec node. These are typically used for development and light computations. In most cases, the job will terminate when you close the terminal.


A bash script that executes things. At the top of your job script, you specify resource requirements for your job (e.g., how many cores, how much memory, a time-limit for the job, etc.) There are two types of jobs: interactive jobs, and batch jobs


LSF is the scheduler that runs on Compute1. It is produced by IBM.


To connect the directories between filesystems


Each physical machine (server) in the cluster is node. There are many nodes in the Compute1 cluster. There are two types of nodes on Compute1: head nodes, and exec nodes.

project directory#

This is your personal data directory on Storage1. Note that it is not $HOME. Your project directory is in /storage1/fs1/rvmartin/Active/, and it is most likely your WUSTL key. There is no size limit. This is for data that you don’t need to share with others. Data that you need to share with others should go in the shared directory. In your jobs, your project directory will be mounted to /my-projects.


The job queues on Compute1 are the locations that you can submit a job to. Our group can use the rvmartin, rvmartin-interactive, general, and general-interactive queues. The number of available slots in a queue can been seen with the bqueues command. Interactive jobs must be submitted to the interactive queues.


The scheduler is the software that manages the cluster (Compute1). Specifically it manages the clusters resources. You submit your job to the scheduler, then the scheduler finds an exec node with available resources (sufficient to satisfy your job’s requirements), allocates the necessary resources on that node for your job, and then starts your job running on that node. All jobs go through the scheduler. Compute1 uses the LSF scheduler produced by IBM.

shared directory#

This is a directory for sharing data between ACAG members. Everyone in ACAG has read/write permissions by default, but you can restrict them with chmod. There is no size limit. On Storage1 this directory is /storage1/fs1/rvmartin/Active/Shared. In your jobs, this directory will be mounted to /shared.


A CPU core. 1 slot is 1 core on a CPU. 500 slots is 500 cores (which will be spread across multiple CPUs).


The filesystem which we store our data on. It is connected to Compute1, but they are not the same thing.