Virtual Machines (VMs)

Virtual Machines (VMs)#

DesignSafe also provides access to dedicated Virtual Machines (VMs) for lightweight and quick-turnaround OpenSees workflows. These systems are distinct from the JupyterHub environment and are optimized for non-parallel simulations.

OpenSees-Express VM#

Execution Model#

  • The OpenSees-Express VM is a submit-only environment.

    • This VM has 1 node, 48 cores and 49GB of RAM (wma-exec-01.tacc.utexas.edu)

    • You cannot SSH into the machine or use it interactively.

    • Jobs are sent to the VM via Tapis, typically using:

      • The Web Portal – OpenSees Tcl only

      • A Tapis job from a Jupyter notebook (via Tapipy)

Shared Environment#

  • Jobs are executed on a single VM node shared across multiple users.

    • Unlike containers on JupyterHub, the VM does not enforce per-user isolation.

    • Users share CPU, memory, and disk I/O, which can cause performance variation under heavy load.

Retirement of Interactive VM#

DesignSafe previously offered a legacy OpenSees Interactive VM, which allowed users to connect to a shared environment for live execution. This environment is being retired in favor of the more scalable and modern JupyterHub system, which offers similar capabilities with better resource management and isolation.

When to Use OpenSees-Express#

  • When you need to run short, sequential Tcl jobs quickly, with no queue delay.

  • When jobs don’t require MPI or multi-threading.

  • When you want to submit jobs through a point-and-click interface with minimal setup.

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