In the coming months, HECC systems including the Pleiades front-end systems (PFEs); Pleiades, Electra, and Aitken compute nodes (including Rome nodes); and GPUs will transition to Red Hat Enterprise Linux (RHEL) from SUSE Linux Enterprise Server (SLES). The purpose is to better align with open source development activities, streamline and reduce ongoing costs, and facilitate interagency collaborative efforts in systems and application software.

Near the end of 2021, jobs requesting SLES12 or SLES15 will not run. We're providing notification well in advance to give some users who will need to revalidate their applications time to plan before the changeover.

The current general schedule for the transition to RHEL (subject to change):

• In progress: The HECC Systems team is working on compute and front-end images; the Application Porting and Productivity (APP) team is assisting with initial testing.
• Mid-August: Limited early access user testing.
  - The APP team will begin coordinating access for some users to help with testing. If you want to be part of this beta activity, please contact support@nas.nasa.gov.
• Mid-September: Open early access user testing begins.
  - All users will be able to test on front ends running RHEL 7. Jobs will be able to specify that RHEL 7 should be used via an option to the qsub command.
• Early December: RHEL 7 moves into production.
  RHEL 7 will become the default operating system selected for new jobs. SLES will remain available on some front ends and for jobs via an option to qsub.
• Late December: SLES12 and SLES15 are no longer available.
  - All user workflows must use RHEL 7 instead of SLES12 or SLES15.

Watch for detailed dates and possible schedule updates for each of these phases in follow-up communications.

If you have any questions or concerns, please contact the Control Room at (800) 331‑8737, (650) 604‑4444, or support@nas.nasa.gov.