Migrating jobs from Oakley or Ruby to Owens

The Oakley cluster was removed from service on December 18, 2018. 

This page includes a summary of differences to keep in mind when migrating jobs from Ruby to Owens.

Guidance for Ruby Users

Hardware Specifications

Regular compute node 28 cores and 128GB of RAM 20 cores and 64GB of RAM
Huge memory node

48 cores and 1.5 TB of RAM, 12 x 2TB drives

(16 nodes in this class)

32 cores and 1TB of RAM 

(1 node in this class)

File Systems

Owens accesses the same OSC mass storage environment as our other clusters. Therefore, users have the same home directory as on the Ruby cluster.

    OWENS ruby
Home directories Accessed through either the  $HOME  environment variable or the tilde notation ( ~username )

Do NOT have symlinks allowing use of the old file system paths.

Please modify your script with the new paths before you submit jobs to Owens cluster



Have the symlinks allowing use of the old file system paths. 

No action is required on your part to continue using your existing job scripts on Oakley cluster




Project directories Located at  /fs/project or /fs/ess
Scratch storage Located at  /fs/scratch or /fs/ess/scratch

See the 2016 Storage Service Upgrades page for details. 

Software Environment

Owens uses the same module system as Ruby.

Use   module load <package to add a software package to your environment. Use   module list   to see what modules are currently loaded and  module avail   to see the modules that are available to load. To search for modules that may not be visible due to dependencies or conflicts, use   module spider 

You can keep up to on the software packages that have been made available on Owens by viewing the Software by System page and selecting the Owens system.

Programming Environment

Like Ruby, Owens supports three compilers: Intel, PGI, and gnu. The default is Intel. To switch to a different compiler, use  module swap intel gnu  or  module swap intel pgi

Owens also use the MVAPICH2 implementation of the Message Passing Interface (MPI), optimized for the high-speed Infiniband interconnect.

In addition, Owens support the Advanced Vector Extensions (AVX2) instruction set, but you must set the correct compiler flags to take advantage of it. In our experience, the Intel and PGI compilers do a much better job than the gnu compilers at optimizing HPC code.

See the Owens Programming Environment page for details.

PBS Batch-Related Command

qpeek Command is not needed on Owens. 

On Ruby, a job’s stdout and stderr data streams, which normally show up on the screen, are written to log files. These log files are stored on a server until the job ends, so you can’t look at them directly. The   qpeek  command allows you to peek at their contents. If you used the PBS header line to join the stdout and stderr streams ( #PBS -j oe ), the two streams are combined in the output log.

On Owens, a job’s stdout and stderr data streams are written to log files stored on the current working directory, i.e. $PBS_O_WORKDIR . You will see the log files immediately after your job get started. 


The Owens cluster will charged at a rate of 1 RU per 10 core-hours.

The Ruby cluster will be charged at a rate of 1 RU per 20 core-hours.

However, Owens will accept partial-node jobs and charge you for the number of cores proportional to the amount of memory your job requests. By contrast, Ruby only accepts full-node jobs and charge for the whole node. 

Below is a comparison of job limits between Owens and Ruby:

  OWENS Ruby
Per User Up to 256 concurrently running jobs and/or up to 3080 processors/cores in use  Up to 40 concurrently running jobs and/or up to 800 processors/cores in use
Per group Up to 384 concurrently running jobs and/or up to 3080 processors/cores in use Up to 80 concurrently running jobs and/or up to 1600 processors/cores in use


Please see Queues and Reservations for Owens for more details.