Sumit Narayan

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Market and customer demands have continued to push the limits of CMOS performance. At-speed test has become a common method to ensure these high performance chips are being shipped to the customers fault-free. However, at-speed tests have been known to create higher-than-average switching activity, which normally is not accounted for in the design of the(More)
In this paper we present a study of I/O access patterns of scientific and general applications on a parallel file system. Understanding I/O access patterns is an essential condition to effectively designing a file system. Supercomputing applications running on these parallel systems make extensive use of parallel file systems taking advantage of faster data(More)
Data integrity is pivotal to the usefulness of any storage system. It ensures that the data stored is free from any modification throughout its existence on the storage medium. Hash functions such as cyclic redundancy checks or check-sums are frequently used to detect data corruption during its transmission to permanent storage or its stay there. Without(More)
Filesystem in Userspace (FUSE) is a typical solution to simplifying writing a new file system. It exports all file system calls to the user-space, giving programmer the ability to implement actual file system code in the user-space but with a small overhead due to context switching and memory copies between the kernel and the user-space. FUSE, however, only(More)
RAID has long been established as an effective way to provide highly reliable disk subsystems. However, reliability in RAID systems comes at the cost of extra disks and somewhat lower performance. In this paper, we examine some mechanisms to reduce this cost in the context of integration with backup processes. These methods are most useful in storage(More)
The total amount of information stored on disks has increased tremendously in recent years with data storage, sharing and backup becoming more important than ever. The demand for storage has not only changed in size, but also in speed, reliability and security. These requirements create a big challenge for storage system architects who aim for a one system(More)
Past: Early Supercomputers CDC-6600, a mainframe computer produced by Control Data Cor po ration (CDC) in 1965 is regarded as the first successful supercomputer. Designed by Seymour Cray and Jim Thornton, the machine was capable of operating at 9 megaflops (MFLOPS)—thousands of times slower than our current desktops. CDC-6600 was also the first machine to(More)