With the increasing explosively of data in network,more and more people pay attention to the networked storage ,currently the main technology of networked storage is NAS ( Network Attached Storage )and SAN ( Storage A...With the increasing explosively of data in network,more and more people pay attention to the networked storage ,currently the main technology of networked storage is NAS ( Network Attached Storage )and SAN ( Storage Area Network ). They are different ,and they are not competed but complement ,they are used in different occasion.To reduce the TOC (total of cost),people hope to merges the two technology :design a united storage network,it can supply the virtues and overcome the drawbacks of the NAS and SAN. This paper analysis and discuss the topic.展开更多
We put forward an optimal disk schedule with n disk requests and prove its optimality mathematically.Generalizing the idea of an optimal disk schedule, we remove the limit of n requests and, at the same time, consider...We put forward an optimal disk schedule with n disk requests and prove its optimality mathematically.Generalizing the idea of an optimal disk schedule, we remove the limit of n requests and, at the same time, consider the dynamically arrival model of disk requests to obtain an algorithm, shortest path first-fit first （SPFF）. This algorithm is based on the shortest path of disk head motion constructed by all the pendent requests. From view of the head moving distance, it has the stronger glohality than SSTF. From view of the head-moving direction, it has the better flexibility than SCAN. Therefore, SPFF keeps the advantage of SCAN and, at the same time, absorbs the strength of SSTF. The algorithm SPFF not only shows the more superiority than other scheduling polices, but also have higher adjustability to meet the computer system＇s different demands.展开更多
文摘With the increasing explosively of data in network,more and more people pay attention to the networked storage ,currently the main technology of networked storage is NAS ( Network Attached Storage )and SAN ( Storage Area Network ). They are different ,and they are not competed but complement ,they are used in different occasion.To reduce the TOC (total of cost),people hope to merges the two technology :design a united storage network,it can supply the virtues and overcome the drawbacks of the NAS and SAN. This paper analysis and discuss the topic.
基金Supported by the National Natural Science Founda-tion of China (60373088)
文摘We put forward an optimal disk schedule with n disk requests and prove its optimality mathematically.Generalizing the idea of an optimal disk schedule, we remove the limit of n requests and, at the same time, consider the dynamically arrival model of disk requests to obtain an algorithm, shortest path first-fit first （SPFF）. This algorithm is based on the shortest path of disk head motion constructed by all the pendent requests. From view of the head moving distance, it has the stronger glohality than SSTF. From view of the head-moving direction, it has the better flexibility than SCAN. Therefore, SPFF keeps the advantage of SCAN and, at the same time, absorbs the strength of SSTF. The algorithm SPFF not only shows the more superiority than other scheduling polices, but also have higher adjustability to meet the computer system＇s different demands.
