NCAR’s HPC resources will be unavailable to users October 17-20 while CISL staff perform preventive maintenance and security updates. The work includes a number of HPC system security patches in addition to regularly scheduled maintenance on Cheyenne’s cooling infrastructure. Progress will be communicated through Notifier emails during the week.

Security updates are planned for Cheyenne and Casper. The hardware serving GLADE home and CISL-installed applications will be upgraded. Network maintenance will make GLADE, Quasar, Stratus, and JupyterHub temporarily unavailable during the maintenance window. These updates are expected to have minimal user-level impact, and CISL staff will verify resource functionality before releasing the systems to the user community.

Scheduler reservations will be put in place on both Cheyenne and Casper to ensure that all user jobs have completed by October 17 as the downtime begins. Any jobs that are queued when the downtime begins will be retained for execution when the systems return to service. Services will be returned to the community incrementally throughout the maintenance window, concluding with Cheyenne general availability.