Robo-line storage: Low latency, high capacity storage systems over geographically distributed networks

Rapid advances in high performance computing are making possible more complete and accurate computer-based modeling of complex physical phenomena, such as weather front interactions, dynamics of chemical reactions, numerical aerodynamic analysis of airframes, and ocean-land-atmosphere interactions. Many of these 'grand challenge' applications are as demanding of the underlying storage system, in terms of their capacity and bandwidth requirements, as they are on the computational power of the processor. A global view of the Earth's ocean chlorophyll and land vegetation requires over 2 terabytes of raw satellite image data. In this paper, we describe our planned research program in high capacity, high bandwidth storage systems. The project has four overall goals. First, we will examine new methods for high capacity storage systems, made possible by low cost, small form factor magnetic and optical tape systems. Second, access to the storage system will be low latency and high bandwidth. To achieve this, we must interleave data transfer at all levels of the storage system, including devices, controllers, servers, and communications links. Latency will be reduced by extensive caching throughout the storage hierarchy. Third, we will provide effective management of a storage hierarchy, extending the techniques already developed for the Log Structured File System. Finally, we will construct a protototype high capacity file server, suitable for use on the National Research and Education Network (NREN). Such research must be a Cornerstone of any coherent program in high performance computing and communications

NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 2

This report contains copies of nearly all of the technical papers and viewgraphs presented at the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Application. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include the following: magnetic disk and tape technologies; optical disk and tape; software storage and file management systems; and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

Proceedings of the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications

The proceedings of the National Space Science Data Center Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications held July 23 through 25, 1991 at the NASA/Goddard Space Flight Center are presented. The program includes a keynote address, invited technical papers, and selected technical presentations to provide a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disk and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 1

Papers and viewgraphs from the conference are presented. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disks and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

The long hold: Storing data at the National Archives

The National Archives is, in many respects, in a unique position. For example, I find people from other organizations describing an archival medium as one which will last for three to five years. At the National Archives, we deal with the centuries, not years. From our perspective, there is no archival medium for data storage, and we do not expect there will ever be one. Predicting the long-term future of information technology beyond a mere five or ten years approaches the occult arts. But one prediction is probably safe. It is that the technology will continue to change, at least until analysts start talking about the post-information age. If we did have a medium which lasted a hundred years or longer, we probably would not have a device capable of reading it. The issue of obsolescence, as opposed to media stability, is more complex and more costly. It is especially complex at the National Archives because of two other aspects of our peculiar position. The first aspect is that we deal with incoherent data. The second is that we are charged with satisfying unknown and unknowable requirements. A brief overview of these aspects is presented

Commissioning of the First Insertion Devices on the 1.5 GeV Storage Ring in MAX IV

When installing an insertion device (ID) in a storage ring the electron beam is affected. The positional displacement and angle deflection is called orbit displacement (OD) and higher order effects such as focusing of the electron beam are referred to as linear optics. The ability to perform multiple simultaneous experiments is crucial in a synchrotron light source such as MAX IV. This is impossible to achieve if one ID affects the output of another through the electron beam, making correction for an ID's effect on the beam imperative. This thesis covers the commissioning process of the first ID to be installed in the MAX IV 1.5 GeV storage ring (R1). The OD and linear optics of an elliptically polarised undulator (EPU) was to be compensated for in a feed forward approach. In essence the commissioning should make the ID transparent to the electron beam. A general procedure was developed using MATLAB and other software and libraries by first solving the problem on a model of the ring and then in the real storage ring. The electron orbit was corrected down to 1 micrometer for most settings of the ID which is close to the noise level of the measuring system of the ring. The commissioning is considered successful and the ID is ready for beamline delivery and will be able to run without affecting other beamlines. It was discovered that some magnetic coils performed 25 percent below their specifications, and that the beta beat of the bare R1 was at its worst 15 percent, something that should be improved for optimal performance of the facility.Ett insättningselement på MAX IV är en förutsättning för det ljus man vill skapa, men påverkar elektronerna som far runt i anläggningen negativt - med hjälp av smarta elektromagneter kan detta lösas. MAX IV är en partikelaccelerator i världsklass. I anläggningen i utkanten av Lund swishar elektronerna i ljusets hastighet runt i enorma ringar av vakuumrör. Till skillnad från vad många tror krockas här däremot elektronerna inte mot något och man kollar varken efter antimateria eller Higgspartiklar. Istället är användningsområdet för MAX IV mer likt det för ett vanligt mikroskop. Ordspråket "att se något i ett nytt ljus" kan inte passa bättre än det man gör på MAX IV. Elektronerna som leds runt de två ringarna i anläggningen är som vilken ström som helst och mäts av forskarna i Ampere. Och precis som när man slår på strömbrytaren på väggen hemma kan man använda strömmen till att skapa ljus. Skillnaden är att istället för en glödlampa har man på MAX IV ett så kallat insättningselement. En annan skillnad till glödlampan hemma är att med insättningselementen och den välskötta elektronstrålen kan man inte bara skapa världens skarpaste och starkaste ljus - utan också ljus i nästan vilken färg man vill! Med det producerade ljuset tittar de forskare som kommer till Lund från hela världen närmare på sammansättningen av mediciner och material för att kunna förstå deras egenskaper och hur de kan användas. För att producera detta superskarpa ljus måste störningar på elektronstrålen hållas till ett minimum, något insättningselementen försvårar. I elementen böjs elektronstrålen upp och ner i en svajande bana vilket skapar själva ljuset innan elektronerna enligt design lämnar elementet med samma vinkel och position i höjd- och sidled. Men trots noggrannheten i konstruktionen och installationen av insättningselementet, kan ett så pass litet fel som 0.01 % i styrkan på insättningselementet få ödesdigra konsekvenser: elektronernas bana förändras så pass mycket att de krockar med väggen på röret och ljuset släcks direkt efter det satts igång. Detta dilemma kan som tur är lösas. En elektromagnet placeras före och efter insättningselementet och genom att ändra styrkan på elektromagneterna kan elektronernas bana korrigeras. Kruxet är att elektronstrålen inte kan korrigeras efter den har försvunnit in i sidan av vakuumröret. För varje inställning på insättningselementet (tänk dig dimmerinställningar till glödlampan) måste det i förväg finnas motsvarande styrkor på elektromagneterna så att i samma ögonblick som insättningselementet ändrar sig gör också elektromagneterna det och kompenserar. Denna metod för korrigering kallas feed forward, i kontrast till den vanligare metoden feed back. Med en hel tabell fylld av sådana inställningar kan MAX IV köras utan problem och producera världens skarpaste och starkaste ljus

Trade-off study of data storage technologies

The need to store and retrieve large quantities of data at modest cost has generated the need for an economical, compact, archival mass storage system. Very significant improvements in the state-of-the-art of mass storage systems have been accomplished through the development of a number of magnetic, electro-optical, and other related devices. This study was conducted in order to do a trade-off between these data storage devices and the related technologies in order to determine an optimum approach for an archival mass data storage system based upon a comparison of the projected capabilities and characteristics of these devices to yield operational systems in the early 1980's

A media maniac's guide to removable mass storage media

This paper addresses at a high level, the many individual technologies available today in the removable storage arena including removable magnetic tapes, magnetic floppies, optical disks and optical tape. Tape recorders represented below discuss logitudinal, serpantine, logitudinal serpantine,and helical scan technologies. The magnetic floppies discussed will be used for personal electronic in-box applications.Optical disks still fill the role for dense long-term storage. The media capacities quoted are for native data. In some cases, 2 KB ASC2 pages or 50 KB document images will be referenced