Scalable management of distributed resources is one of the major
challenges in deployment of large-scale clusters.  Management includes
transparent fault tolerance, efficient allocation of resources, and
support for all the needs of parallel applications: parallel I/O,
deterministic behavior, and responsiveness.  These requirements are
daunting with commodity hardware and operating systems since they were
not designed to support a global, single management view of a
large-scale system. In this paper we propose a small set of hardware
mechanisms in the cluster interconnect to facilitate the
implementation of a simple yet powerful global operating system.  This
system, which can be thought of as a coarse-grain SIMD operating
system, allows commodity clusters to grow to thousands of nodes while
still retaining the usability and responsiveness of the single-node
workstation.  Our results on a software prototype show that it is
possible to implement efficient and scalable system software using the
proposed set of mechanisms.