Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528232
L. Golubchik, R. Muntz, R. Watson
In recent years advances in computational speed have been the main focus of research and development in high performance computing. In comparison, the improvement in I/O performance has been modest. Faster processing speeds have created a need for faster I/O as well as for the storage and retrieval of vast amounts of data. The technology needed to develop these mass storage systems exists today. Robotic storage libraries are vital components of such systems. However, they normally exhibit high latency and long transmission times. We analyze the performance of robotic storage libraries and study striping as a technique for improving response time. Although striping has been extensively studied in the content of disk arrays, the architectural differences between robotic storage libraries and arrays of disks suggest that a separate study of striping techniques in such libraries would be beneficial.
{"title":"Analysis of striping techniques in robotic storage libraries","authors":"L. Golubchik, R. Muntz, R. Watson","doi":"10.1109/MASS.1995.528232","DOIUrl":"https://doi.org/10.1109/MASS.1995.528232","url":null,"abstract":"In recent years advances in computational speed have been the main focus of research and development in high performance computing. In comparison, the improvement in I/O performance has been modest. Faster processing speeds have created a need for faster I/O as well as for the storage and retrieval of vast amounts of data. The technology needed to develop these mass storage systems exists today. Robotic storage libraries are vital components of such systems. However, they normally exhibit high latency and long transmission times. We analyze the performance of robotic storage libraries and study striping as a technique for improving response time. Although striping has been extensively studied in the content of disk arrays, the architectural differences between robotic storage libraries and arrays of disks suggest that a separate study of striping techniques in such libraries would be beneficial.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121047448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528216
Jeff K. Deutsch, M. Gary
Most modern high performance storage systems store data in large repositories of removable media volumes. Management of the removable volumes is performed by a software module known as a physical volume library (PVL). To meet performance and scalability requirements, a PVL can be asked to mount multiple removable media volumes for use by a single client for parallel data transfer. Mounting sets of volumes creates an environment in which it is possible for multiple client requests to deadlock while attempting to gain access to storage resources. Scenarios leading to deadlock in a PVL include multiple client requests that contend for the same cartridge(s), and client requests that vie for a limited set of drive resources. These deadlock scenarios are further complicated by the potential for volumes to be mounted out-of-order (for example, by automatic cartridge loaders or human operators). This paper begins by introducing those PVL requirements which create the possibility of deadlock resolution and how they might be applied in a PVL. This leads to a design for a PVL that addresses deadlock scenarios. Following the design presentation is a discussion of possible design enhancements. We end with a case study of an actual implementation of the PVL design in the high performance storage system (HPSS).
{"title":"Physical volume library deadlock avoidance in a striped media environment","authors":"Jeff K. Deutsch, M. Gary","doi":"10.1109/MASS.1995.528216","DOIUrl":"https://doi.org/10.1109/MASS.1995.528216","url":null,"abstract":"Most modern high performance storage systems store data in large repositories of removable media volumes. Management of the removable volumes is performed by a software module known as a physical volume library (PVL). To meet performance and scalability requirements, a PVL can be asked to mount multiple removable media volumes for use by a single client for parallel data transfer. Mounting sets of volumes creates an environment in which it is possible for multiple client requests to deadlock while attempting to gain access to storage resources. Scenarios leading to deadlock in a PVL include multiple client requests that contend for the same cartridge(s), and client requests that vie for a limited set of drive resources. These deadlock scenarios are further complicated by the potential for volumes to be mounted out-of-order (for example, by automatic cartridge loaders or human operators). This paper begins by introducing those PVL requirements which create the possibility of deadlock resolution and how they might be applied in a PVL. This leads to a design for a PVL that addresses deadlock scenarios. Following the design presentation is a discussion of possible design enhancements. We end with a case study of an actual implementation of the PVL design in the high performance storage system (HPSS).","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115196778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528213
Y. Birk
A video-on-demand (VOD) storage server is a parallel, storage-centric system used for playing a large number of relatively slow streams of compressed digitized video and audio concurrently. Data is read from disks in relatively large chunks, and is then "streamed" out onto a distribution network. The primary design goal is to maximize the ratio of the number of concurrent streams to system cost while guaranteeing glitch-free operation. This paper focuses on load-balancing for the purpose of providing throughput that is independent of viewing choices. At the interdisk level, data striping is the obvious solution, but may lead to a quadratic growth of RAM buffer requirements with system size. At the intradisk level multizone recording results in variable disk throughput. Deterministic schemes for solving each problem are discussed, as well as their joint operation. Finally, efficient staging of data from tertiary storage devices to disk is shown to be possible.
{"title":"Deterministic load-balancing schemes for disk-based video-on-demand storage servers","authors":"Y. Birk","doi":"10.1109/MASS.1995.528213","DOIUrl":"https://doi.org/10.1109/MASS.1995.528213","url":null,"abstract":"A video-on-demand (VOD) storage server is a parallel, storage-centric system used for playing a large number of relatively slow streams of compressed digitized video and audio concurrently. Data is read from disks in relatively large chunks, and is then \"streamed\" out onto a distribution network. The primary design goal is to maximize the ratio of the number of concurrent streams to system cost while guaranteeing glitch-free operation. This paper focuses on load-balancing for the purpose of providing throughput that is independent of viewing choices. At the interdisk level, data striping is the obvious solution, but may lead to a quadratic growth of RAM buffer requirements with system size. At the intradisk level multizone recording results in variable disk throughput. Deterministic schemes for solving each problem are discussed, as well as their joint operation. Finally, efficient staging of data from tertiary storage devices to disk is shown to be possible.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114142553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528229
Betty Jo Armstead, Stephen Prahst
In 1990, a technical team at NASA Lewis Research Center, Cleveland, Ohio, began defining a mass storage service to provide long-term archival storage, short-term storage for very large files, distributed NFS access, and backup services for critical data that resides on workstations and PCs. Because of software availability and budgets, the total service was phased in over three years. During the process of building the service from the commercial technologies available, our mass storage team refined the original vision and learned from the problems and mistakes that had occurred. We also enhanced some technologies to better meet the needs of users and system administrators. This paper describes our team's journey from dream to reality, outlines some of the problem areas that still exist, and suggests some solutions.
{"title":"Implementation of a campus-wide distributed mass storage service: the dream vs. reality","authors":"Betty Jo Armstead, Stephen Prahst","doi":"10.1109/MASS.1995.528229","DOIUrl":"https://doi.org/10.1109/MASS.1995.528229","url":null,"abstract":"In 1990, a technical team at NASA Lewis Research Center, Cleveland, Ohio, began defining a mass storage service to provide long-term archival storage, short-term storage for very large files, distributed NFS access, and backup services for critical data that resides on workstations and PCs. Because of software availability and budgets, the total service was phased in over three years. During the process of building the service from the commercial technologies available, our mass storage team refined the original vision and learned from the problems and mistakes that had occurred. We also enhanced some technologies to better meet the needs of users and system administrators. This paper describes our team's journey from dream to reality, outlines some of the problem areas that still exist, and suggests some solutions.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131448436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528234
A. Chervenak, D. Patterson, R. Katz
We evaluate storage system alternatives for movies-on-demand video servers. We begin by characterizing the movies-on-demand workload. We briefly discuss performance in disk arrays. First, we study disk farms in which one movie is stored per disk. This is a simple scheme, but it wastes substantial disk bandwidth, because disks holding less popular movies are underutilized; also, good performance requires that movies be replicated to reflect the user request pattern. Next, we examine disk farms in which movies are striped across disks, and find that striped video servers offer nearly full utilization of the disks by achieving better load balancing. For the remainder of the paper, we concentrate on tertiary storage systems. We evaluate the use of storage hierarchies for video service. These hierarchies include a tertiary library along with a disk farm. We examine both magnetic tape libraries and optical disk jukeboxes. We show that, unfortunately, the performance of neither tertiary system performs adequately as part of a storage hierarchy to service the predicted distribution of movie accesses. We suggest changes to tertiary libraries that would make them better-suited to these applications.
{"title":"Storage systems for movies-on-demand video servers","authors":"A. Chervenak, D. Patterson, R. Katz","doi":"10.1109/MASS.1995.528234","DOIUrl":"https://doi.org/10.1109/MASS.1995.528234","url":null,"abstract":"We evaluate storage system alternatives for movies-on-demand video servers. We begin by characterizing the movies-on-demand workload. We briefly discuss performance in disk arrays. First, we study disk farms in which one movie is stored per disk. This is a simple scheme, but it wastes substantial disk bandwidth, because disks holding less popular movies are underutilized; also, good performance requires that movies be replicated to reflect the user request pattern. Next, we examine disk farms in which movies are striped across disks, and find that striped video servers offer nearly full utilization of the disks by achieving better load balancing. For the remainder of the paper, we concentrate on tertiary storage systems. We evaluate the use of storage hierarchies for video service. These hierarchies include a tertiary library along with a disk farm. We examine both magnetic tape libraries and optical disk jukeboxes. We show that, unfortunately, the performance of neither tertiary system performs adequately as part of a storage hierarchy to service the predicted distribution of movie accesses. We suggest changes to tertiary libraries that would make them better-suited to these applications.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122062867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528237
E. Kapetanios, Ralf Kramer
Over the last few years, dramatic increases and advances in mass storage for both secondary and tertiary storage made possible the handling of big amounts of data (for example, satellite data, complex scientific experiments, and so on). However, to the full use of these advances, metadata for data analysis and interpretation, as well as the complexity of managing and accessing large datasets through intelligent and efficient methods, are still considered to be the main challenges to the information-science community when dealing with large databases. Scientific data must be analyzed and interpreted by metadata, which has a descriptive role for the underlying data. Metadata can be, partly, a priori definable according to the domain of discourse under consideration (for example, atmospheric chemistry) and the conceptualization of the information system to be built. It may also be extracted by using learning methods from time-series measurement and observation data. In this paper, a knowledge-based management system (KBMS) is presented for the extraction and management of metadata in order to bridge the gap between data and information. The KBMS is a component of an intelligent information system based upon a federated architecture, also including a database management system for time-series-oriented data and a visualization system.
{"title":"A knowledge-based system approach for scientific data analysis and the notion of metadata","authors":"E. Kapetanios, Ralf Kramer","doi":"10.1109/MASS.1995.528237","DOIUrl":"https://doi.org/10.1109/MASS.1995.528237","url":null,"abstract":"Over the last few years, dramatic increases and advances in mass storage for both secondary and tertiary storage made possible the handling of big amounts of data (for example, satellite data, complex scientific experiments, and so on). However, to the full use of these advances, metadata for data analysis and interpretation, as well as the complexity of managing and accessing large datasets through intelligent and efficient methods, are still considered to be the main challenges to the information-science community when dealing with large databases. Scientific data must be analyzed and interpreted by metadata, which has a descriptive role for the underlying data. Metadata can be, partly, a priori definable according to the domain of discourse under consideration (for example, atmospheric chemistry) and the conceptualization of the information system to be built. It may also be extracted by using learning methods from time-series measurement and observation data. In this paper, a knowledge-based management system (KBMS) is presented for the extraction and management of metadata in order to bridge the gap between data and information. The KBMS is a component of an intelligent information system based upon a federated architecture, also including a database management system for time-series-oriented data and a visualization system.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130612154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528217
B. Kobler, J. Berbert, Parris Caulk, P. C. Hariharan
Mission to Planet Earth (MTPE) is a long-term NASA research mission to study the processes leading to global climate change. The EOS Data and Information System (EOSDIS) is the component within MTPE that will provide the Earth science community with easy, affordable, and reliable access to Earth science data. EOSDIS is a distributed system, with major facilities at eight Distributed Active Archive Centers (DAACs) located throughout the United States. At the DAACs the Science Data Processing Segment (SDPS) will receive, process, archive, and manage all data. It is estimated that several hundred gigaflops of processing power will be required to process and archive the several terabytes of new data that will be generated and distributed daily. Thousands of science users and perhaps several hundred thousand nonscience users will access the system.
{"title":"Architecture and design of storage and data management for the NASA Earth observing system Data and Information System (EOSDIS)","authors":"B. Kobler, J. Berbert, Parris Caulk, P. C. Hariharan","doi":"10.1109/MASS.1995.528217","DOIUrl":"https://doi.org/10.1109/MASS.1995.528217","url":null,"abstract":"Mission to Planet Earth (MTPE) is a long-term NASA research mission to study the processes leading to global climate change. The EOS Data and Information System (EOSDIS) is the component within MTPE that will provide the Earth science community with easy, affordable, and reliable access to Earth science data. EOSDIS is a distributed system, with major facilities at eight Distributed Active Archive Centers (DAACs) located throughout the United States. At the DAACs the Science Data Processing Segment (SDPS) will receive, process, archive, and manage all data. It is estimated that several hundred gigaflops of processing power will be required to process and archive the several terabytes of new data that will be generated and distributed daily. Thousands of science users and perhaps several hundred thousand nonscience users will access the system.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131283999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528228
D. C. Humes, Juliet Z. Pao
There is a trend in institutions with high-performance computing and data management requirements to explore mass storage systems with peripherals directly attached to a high-speed network. The Distributed Mass Storage System (DMSS) Project at the NASA Langley Research Center (LaRC) has placed such a system into production use. This paper describes the DMSS system and relates experiences from production use.
{"title":"Experiences from NASA/Langley's DMSS Project","authors":"D. C. Humes, Juliet Z. Pao","doi":"10.1109/MASS.1995.528228","DOIUrl":"https://doi.org/10.1109/MASS.1995.528228","url":null,"abstract":"There is a trend in institutions with high-performance computing and data management requirements to explore mass storage systems with peripherals directly attached to a high-speed network. The Distributed Mass Storage System (DMSS) Project at the NASA Langley Research Center (LaRC) has placed such a system into production use. This paper describes the DMSS system and relates experiences from production use.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123006730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528212
W. Hanlon, E. Fener
The business of healthcare management is changing rapidly, heading in the direction of managed care, capitation, and integrated delivery systems. Information management is crucial to the success and competitiveness of these new care delivery systems. A major goal of medical systems designers is to develop a model for a multimedia, computer-based patient medical record (CPR). The fundamental function of a CPR system is to record, monitor, retrieve, and analyze all events associated with an encounter between the patient and the healthcare system. Data components of the CPR include all forms of multimedia information, gathered from various departments within the institution. Users of the data will be diverse and widely distributed. The amount of digital data generated will be approximately two terabytes (TB) of information per year for a medium-sized metropolitan medical institution. Most of the data (by volume) are diagnostic radiological images. This information must remain on-line or near-line for 7-10 years, or longer in many cases. Image and other data of the CPR will be stored as self-defining information objects in a data repository (DR). The DR will be comprised of distributed storage subsystems and a high-level communications interface. Mass storage subsystems and information management systems being developed now will be core technologies of the DR and the CPR.
{"title":"Data storage and management requirements for the multimedia computer-based patient medical record","authors":"W. Hanlon, E. Fener","doi":"10.1109/MASS.1995.528212","DOIUrl":"https://doi.org/10.1109/MASS.1995.528212","url":null,"abstract":"The business of healthcare management is changing rapidly, heading in the direction of managed care, capitation, and integrated delivery systems. Information management is crucial to the success and competitiveness of these new care delivery systems. A major goal of medical systems designers is to develop a model for a multimedia, computer-based patient medical record (CPR). The fundamental function of a CPR system is to record, monitor, retrieve, and analyze all events associated with an encounter between the patient and the healthcare system. Data components of the CPR include all forms of multimedia information, gathered from various departments within the institution. Users of the data will be diverse and widely distributed. The amount of digital data generated will be approximately two terabytes (TB) of information per year for a medium-sized metropolitan medical institution. Most of the data (by volume) are diagnostic radiological images. This information must remain on-line or near-line for 7-10 years, or longer in many cases. Image and other data of the CPR will be stored as self-defining information objects in a data repository (DR). The DR will be comprised of distributed storage subsystems and a high-level communications interface. Mass storage subsystems and information management systems being developed now will be core technologies of the DR and the CPR.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133423434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-11DOI: 10.1109/MASS.1995.528211
D. Dixon
The European Centre for Medium-Range Weather Forecasts (ECMWF) has for many years operated a large mass-storage system based on CFS/DataTree. The CFS system will need replacement before the end of the decade, and ECMWF accordingly embarked on a study of available systems which might be suitable. What we found was that, for various reasons, none of the systems available on the market met our needs. Three particular areas stood out in which commercial systems either could not meet our end-of-decade requirement or in which the existing CFS system was already superior. Over the past two years, during our active pursuit of a system that might satisfactorily follow in the footsteps of CFS, we have learned in fact just how good the existing system was. Our initial assumptions that the market would provide, and clearly indicate, an appropriate successor, were quickly proven over-optimistic and we were forced to make the necessary plans to extend the life of CFS. By making common cause with a number of ether sites with a similar background, we were able to indicate more forcibly to the suppliers the direction in which our dissatisfaction lay; although the time scales of the intended installation meant that we were unable to await the delivery of systems with superior specifications, it also meant that we went into a tendering exercise with the knowledge that we might well have to install a noncompliant system that the supplier would undertake to enhance. By the time of the Monterey Symposium, the selected successor system will be only weeks away from acceptance; and we shall be able to present the decisions and plans that have led to the selection of that solution. The remaining tasks will be to commission the system, develop and integrate the necessary services, and to phase over operations from the old CFS system to the new one, which includes the copying of up to 60 terabytes of old data.
{"title":"Changing horses in mid-stream (or, how do you follow one of the most successful acts in mass storage?)","authors":"D. Dixon","doi":"10.1109/MASS.1995.528211","DOIUrl":"https://doi.org/10.1109/MASS.1995.528211","url":null,"abstract":"The European Centre for Medium-Range Weather Forecasts (ECMWF) has for many years operated a large mass-storage system based on CFS/DataTree. The CFS system will need replacement before the end of the decade, and ECMWF accordingly embarked on a study of available systems which might be suitable. What we found was that, for various reasons, none of the systems available on the market met our needs. Three particular areas stood out in which commercial systems either could not meet our end-of-decade requirement or in which the existing CFS system was already superior. Over the past two years, during our active pursuit of a system that might satisfactorily follow in the footsteps of CFS, we have learned in fact just how good the existing system was. Our initial assumptions that the market would provide, and clearly indicate, an appropriate successor, were quickly proven over-optimistic and we were forced to make the necessary plans to extend the life of CFS. By making common cause with a number of ether sites with a similar background, we were able to indicate more forcibly to the suppliers the direction in which our dissatisfaction lay; although the time scales of the intended installation meant that we were unable to await the delivery of systems with superior specifications, it also meant that we went into a tendering exercise with the knowledge that we might well have to install a noncompliant system that the supplier would undertake to enhance. By the time of the Monterey Symposium, the selected successor system will be only weeks away from acceptance; and we shall be able to present the decisions and plans that have led to the selection of that solution. The remaining tasks will be to commission the system, develop and integrate the necessary services, and to phase over operations from the old CFS system to the new one, which includes the copying of up to 60 terabytes of old data.","PeriodicalId":345074,"journal":{"name":"Proceedings of IEEE 14th Symposium on Mass Storage Systems","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133930542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：