We are members of Livermore Computing (LC) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. LC is home to some of the world’s fastest supercomputers, including Sequoia, the 4th fastest in the world. Scientists use our High Performance Computing (HPC) machines to run physical simulations: from geology, astronomy, and cardiac arrhythmia, to the US nuclear stockpile and other problems of national interest. We bring in the machines, keep them running fast, and provide scientists with the tools they need to run these simulations. We have varying roles in system administration, software development, data archiving, visualization, operations, facilities management, user interfaces to the center and data, user support, and research. Our developers lead and contribute to many open source projects: From Linux kernel infrastructure like file systems, such as Lustre and ZFS on Linux; to industry spanning cluster management tools, such as SLURM, Flux, and pdsh; and beyond to all aspects of scientific and cluster computing with spack, STAT, and SCR. For more info about our various open source efforts, visit https://software.llnl.gov/. For more information about our center, visit https://hpc.llnl.gov/. So if you have a question about any part of running or using supercomputers at HPC centers, we’ll be back at 1 pm ET, feel free to ask and we will answer as many questions as we can! EDIT: Good Morning from the West Coast! We see that everyone has started asking fantastic questions! We will start answering some questions! EDIT 2: Thanks for all the great questions. We hope to come back soon. Next time, we plan to try to answer your questions in parallel! Learn more, contact, or apply to join us here: https://computation.llnl.gov/. Our thanks to Reddit and r/Science for providing us with the opportunity to have this AUA! We leave you with a photo of some of us in front of Sequoia today! Have a nice day everyone! :)