Holistic Evaluation of Lightweight Operating Systems using the PERCU Method

The scale of Leadership Class Systems presents unique challenges to the features and performance of operating system services. This paper reports results of comprehensive evaluations of two Light Weight Operating Systems (LWOS), Cray's Catamount Virtual Node (CVN) and Linux Environment (CLE) operating systems, on the exact same large-scale hardware. The evaluation was carried out over a 5-month period on NERSC's 19,480 core Cray XT-4, Franklin, using a comprehensive evaluation method that spans Performance, Effectiveness, Reliability, Consistency and Usability criteria for all major subsystems and features. The paper presents the results of the comparison between CVN and CLE, evaluates their relative strengths, and reports observations regarding the world's largest Cray XT-4 as well

Holistic Evaluation of Lightweight Operating Systems using the PERCU Method

The scale of Leadership Class Systems presents unique challenges to the features and performance of operating system services. This paper reports results of comprehensive evaluations of two Light Weight Operating Systems (LWOS), Cray's Catamount Virtual Node (CVN) and Linux Environment (CLE) operating systems, on the exact same large-scale hardware. The evaluation was carried out over a 5-month period on NERSC's 19,480 core Cray XT-4, Franklin, using a comprehensive evaluation method that spans Performance, Effectiveness, Reliability, Consistency and Usability criteria for all major subsystems and features. The paper presents the results of the comparison between CVN and CLE, evaluates their relative strengths, and reports observations regarding the world's largest Cray XT-4 as well

How Are We Doing? A Self-Assessment of the Quality of Services and Systems at NERSC, 2005-2006

This is the sixth self-assessment of the systems and services provided by the U.S. Department of Energy's National Energy Research Scientific Computing Center, describing many of the efforts of the NERSC staff to support advanced computing for scientific discovery. The report is organized along the 10 goals set by our staff and outlines how we are working to meet those goals. Our staff applies experience and expertise to provide world-class systems and unparalleled services for NERSC users. At the same time, members of our organization are leading contributors to advancing the field of high-performance computing through conference presentations, published papers, collaborations with scientific researchers and through regular meetings with members of similar institutions. In the fast-moving realm of high-performance computing, adopting the latest technology while reliably delivering critical resources can be a challenge, but we believe that this self-assessment demonstrates that NERSC continues to excel on both counts

Building the Teraflops/Petabytes Production Computing Center

In just one decade, the 1990s, supercomputer centers have undergone two fundamental transitions which require rethinking their operation and their role in high performance computing. The first transition in the early to mid-1990s resulted from a technology change in high performance computing architecture. Highly parallel distributed memory machines built from commodity parts increased the operational complexity of the supercomputer center, and required the introduction of intellectual services as equally important components of the center. The second transition is happening in the late 1990s as centers are introducing loosely coupled clusters of SMPs as their premier high performance computing platforms, while dealing with an ever-increasing volume of data. In addition, increasing network bandwidth enables new modes of use of a supercomputer center, in particular, computational grid applications. In this paper we describe what steps NERSC is taking to address these issues and stay at the leading edge of supercomputing centers

Franklin: User Experiences

The newest workhorse of the National Energy Research Scientific Computing Center is a Cray XT4 with 9,736 dual core nodes. This paper summarizes Franklin user experiences from friendly early user period to production period. Selected successful user stories along with top issues affecting user experiences are presented

Creating science-driven computer architecture: A new patch to scientific leadership

We believe that it is critical for the future of high end computing in the United States to bring into existence a new class of computational capability that is optimal for science. In recent years scientific computing has increasingly become dependent on hardware that is designed and optimized for commercial applications. Science in this country has greatly benefited from the improvements in computers that derive from advances in microprocessors following Moore's Law, and a strategy of relying on machines optimized primarily for business applications. However within the last several years, in part because of the challenge presented by the appearance of the Japanese Earth Simulator, the sense has been growing in the scientific community that a new strategy is needed. A more aggressive strategy than reliance only on market forces driven by business applications is necessary in order to achieve a better alignment between the needs of scientific computing and the platforms available. The United States should undertake a program that will result in scientific computing capability that durably returns the advantage to American science, because doing so is crucial to the country's future. Such a strategy must also be sustainable. New classes of computer designs will not only revolutionize the power of supercomputing for science, but will also affect scientific computing at all scales. What is called for is the opening of a new frontier of scientific capability that will ensure that American science is greatly enabled in its pursuit of research in critical areas such as nanoscience, climate prediction, combustion, modeling in the life sciences, and fusion energy, as well as in meeting essential needs for national security. In this white paper we propose a strategy for accomplishing this mission, pursuing different directions of hardware development and deployment, and establishing a highly capable networking and grid infrastructure connecting these platforms to the broad research community

Report of the Workshop on Petascale Systems Integration for Large Scale Facilities

There are significant issues regarding Large Scale System integration that are not being addressed in other forums such as current research portfolios or vendor user groups. Unfortunately, the issues in the area of large-scale system integration often fall into a netherworld; not research, not facilities, not procurement, not operations, not user services. Taken together, these issues along with the impact of sub-optimal integration technology means the time required to deploy, integrate and stabilize large scale system may consume up to 20 percent of the useful life of such systems. Improving the state of the art for large scale systems integration has potential to increase the scientific productivity of these systems. Sites have significant expertise, but there are no easy ways to leverage this expertise among them . Many issues inhibit the sharing of information, including available time and effort, as well as issues with sharing proprietary information. Vendors also benefit in the long run from the solutions to issues detected during site testing and integration. There is a great deal of enthusiasm for making large scale system integration a full-fledged partner along with the other major thrusts supported by funding agencies in the definition, design, and use of a petascale systems. Integration technology and issues should have a full 'seat at the table' as petascale and exascale initiatives and programs are planned. The workshop attendees identified a wide range of issues and suggested paths forward. Pursuing these with funding opportunities and innovation offers the opportunity to dramatically improve the state of large scale system integration