This page includes a summary of differences to keep in mind when migrating jobs from Ruby to Owens.
Guidance for Ruby Users
|OWENS (PER NODE)||Ruby (PER NODE)|
|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)
Owens accesses the same OSC mass storage environment as our other clusters. Therefore, users have the same home directory as on the Ruby cluster.
|Home directories||Accessed through either the
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
|Scratch storage||Located at
See the 2016 Storage Service Upgrades page for details.
Owens uses the same module system as Ruby.
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.
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:
|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.