Overview of File Systems

OSC has several different file systems where you can create files and directories. The characteristics of those systems and the policies associated with them determine their suitability for any particular purpose. This section describes the characteristics and policies that you should take into consideration in selecting a file system to use.

The various file systems are described in subsequent sections.

Changes of Default Memory Limits

Problem Description

Our current GPFS file system is a distributed process with significant interactions between the clients. As the compute nodes being GPFS flle system clients, a certain amount of memory of each node needs to be reserved for these interactions. As a result, the maximum physical memory of each node allowed to be used by users' jobs is reduced, in order to keep the healthy performance of the file system. In addition, using swap memory is not allowed.  

The table below summarizes the maximum physical memory allowed for each type of nodes on our systems:

Technical Specifications

The following are technical specifications for Owens.  

Number of Nodes

824 nodes

Number of CPU Sockets

1,648 (2 sockets/node)

Number of CPU Cores

23,392 (28 cores/node)

Cores Per Node

28 cores/node (48 cores/node for Huge Mem Nodes)

Local Disk Space Per Node

~1,500GB in /tmp

2016 Storage Service Upgrades

On July 12th, 2016 OSC migrated its old GPFS and Lustre filesystems to new Project and Scratch services, respectively. We've moved 1.22 PB of data, and the new capacities are 3.4 PB for Project, and 1.1 PB for Scratch. If you store data on these services, there are a few important details to note.

Messages from sbatch

sbatch messages

shell warning

Submitting a job without specifying the proper shell will return a warning like below:

sbatch: WARNING: Job script lacks first line beginning with #! shell. Injecting '#!/bin/bash' as first line of job script.


If an error is encountered, the job is rejected.

Not specifying a project account

It is required to specify an account for a job to run. Please use the --account=<project-code> option to do this.


TIP: Remember to check the menu to the right of the page for related pages with more information about Owens' specifics.

OSC's Owens cluster being installed in 2016 is a Dell-built, Intel® Xeon® processor-based supercomputer.


ParMETIS (Parallel Graph Partitioning and Fill-reducing Matrix Ordering) is an MPI-based parallel library that implements a variety of algorithms for partitioning unstructured graphs, meshes, and for computing fill-reducing orderings of sparse matrices. ParMETIS extends the functionality provided by METIS and includes routines that are especially suited for parallel AMR computations and large scale numerical simulations. The algorithms implemented in ParMETIS are based on the parallel multilevel k-way graph-partitioning, adaptive repartitioning, and parallel multi-constrained partitioning schemes developed in Karypis lab.

METIS (Serial Graph Partitioning and Fill-reducing Matrix Ordering) is a set of serial programs for partitioning graphs, partitioning finite element meshes, and producing fill reducing orderings for sparse matrices. The algorithms implemented in METIS are based on the multilevel recursive-bisection, multilevel k-way, and multi-constraint partitioning schemes developed in Karypis lab.

Firewall and Proxy Settings

Connections to OSC

In order for users to access OSC resources through the web your firewall rules should allow for connections to the following publicly-facing IP ranges.  Otherwise, users may be blocked or denied access to our services.


The followingg TCP ports should be opened:

  • 80 (HTTP)
  • 443 (HTTPS)
  • 22 (SSH)

The following domain should be allowed: