Performance and energy consumption of a solid state disk(SSD) highly depend on file systems and I/O schedulers in operating systems. To find an optimal combination of a file system and an I/O scheduler for SSDs, we us...Performance and energy consumption of a solid state disk(SSD) highly depend on file systems and I/O schedulers in operating systems. To find an optimal combination of a file system and an I/O scheduler for SSDs, we use a metric called the aggregative indicator(AI), which is the ratio of SSD performance value(e.g., data transfer rate in MB/s or throughput in IOPS) to that of energy consumption for an SSD. This metric aims to evaluate SSD performance per energy consumption and to study the SSD which delivers high performance at low energy consumption in a combination of a file system and an I/O scheduler. We also propose a metric called Cemp to study the changes of energy consumption and mean performance for an Intel SSD(SSD-I) when it provides the largest AI, lowest power, and highest performance, respectively. Using Cemp, we attempt to find the combination of a file system and an I/O scheduler to make SSD-I deliver a smooth change in energy consumption. We employ Filebench as a workload generator to simulate a wide range of workloads(i.e., varmail, fileserver, and webserver), and explore optimal combinations of file systems and I/O schedulers(i.e., optimal values of AI) for tested SSDs under different workloads. Experimental results reveal that the proposed aggregative indicator is comprehensive for exploring the optimal combination of a file system and an I/O scheduler for SSDs, compared with an individual metric.展开更多
In this paper, we propose a fast and simple system emulator, called a system performance emulator(SPE), to evaluate long read operations.The SPE estimates how much system-wide performance is enhanced by using a faster...In this paper, we propose a fast and simple system emulator, called a system performance emulator(SPE), to evaluate long read operations.The SPE estimates how much system-wide performance is enhanced by using a faster solid state disk(SSD).By suspending a CPU for a certain time during direct memory access(DMA) transfer and subtracting this suspended time from the total DMA time, the SPE estimates the improvement in system performance expected from an enhanced SSD prior to its manufacture.We also examine the relation between storage performance and system performance using the SPE.展开更多
随着大数据时代的到来,固态硬盘已经逐渐在大型数据中心得到应用。作为使用最广泛的RAID技术,RAID5也开始应用于固态硬盘阵列,以保证数据的可靠性。然而,RAID5中校验信息需要频繁地更新,尤其在随机访问中,频繁地更新校验信息将会对固态...随着大数据时代的到来,固态硬盘已经逐渐在大型数据中心得到应用。作为使用最广泛的RAID技术,RAID5也开始应用于固态硬盘阵列,以保证数据的可靠性。然而,RAID5中校验信息需要频繁地更新,尤其在随机访问中,频繁地更新校验信息将会对固态硬盘阵列的性能和寿命造成很大的影响,针对此问题,提出PA-SSD(Parity-Aware Solid State Disk)控制器设计,从RAID5控制器得到校验信息的逻辑地址,在SSD控制器中设置一个缓存Pcache,暂存更新后的校验信息,并在SSD中将数据和校验分开布局,设置专门的区域存放校验信息。通过实验仿真测试,提出的方法能有效地减少校验信息对SSD的写操作,并且减少了SSD的擦除次数,提升了SSD阵列的性能和寿命。展开更多
基金supported by the National Basic Research Program(973)of China(No.2011CB302303)the National Natural Science Foundation of China(No.60933002)+1 种基金the National High-Tech R&D Program(863)of China(No.2013AA013203)the U.S. National Science Foundation under Grants CCF0845257(CAREER),CNS-0917137(CSR),CNS-0757778(CSR),CCF-0742187(CPA),CNS-0831502(CyberTrust),CNS-0855251(CRI),OCI-0753305(CI-TEAM),DUE-0837341(CCLI),and DUE-0830831(SFS)
文摘Performance and energy consumption of a solid state disk(SSD) highly depend on file systems and I/O schedulers in operating systems. To find an optimal combination of a file system and an I/O scheduler for SSDs, we use a metric called the aggregative indicator(AI), which is the ratio of SSD performance value(e.g., data transfer rate in MB/s or throughput in IOPS) to that of energy consumption for an SSD. This metric aims to evaluate SSD performance per energy consumption and to study the SSD which delivers high performance at low energy consumption in a combination of a file system and an I/O scheduler. We also propose a metric called Cemp to study the changes of energy consumption and mean performance for an Intel SSD(SSD-I) when it provides the largest AI, lowest power, and highest performance, respectively. Using Cemp, we attempt to find the combination of a file system and an I/O scheduler to make SSD-I deliver a smooth change in energy consumption. We employ Filebench as a workload generator to simulate a wide range of workloads(i.e., varmail, fileserver, and webserver), and explore optimal combinations of file systems and I/O schedulers(i.e., optimal values of AI) for tested SSDs under different workloads. Experimental results reveal that the proposed aggregative indicator is comprehensive for exploring the optimal combination of a file system and an I/O scheduler for SSDs, compared with an individual metric.
基金Project supported by the Second Brain Korea 21 Project and Samsung Electronics
文摘In this paper, we propose a fast and simple system emulator, called a system performance emulator(SPE), to evaluate long read operations.The SPE estimates how much system-wide performance is enhanced by using a faster solid state disk(SSD).By suspending a CPU for a certain time during direct memory access(DMA) transfer and subtracting this suspended time from the total DMA time, the SPE estimates the improvement in system performance expected from an enhanced SSD prior to its manufacture.We also examine the relation between storage performance and system performance using the SPE.
文摘随着大数据时代的到来,固态硬盘已经逐渐在大型数据中心得到应用。作为使用最广泛的RAID技术,RAID5也开始应用于固态硬盘阵列,以保证数据的可靠性。然而,RAID5中校验信息需要频繁地更新,尤其在随机访问中,频繁地更新校验信息将会对固态硬盘阵列的性能和寿命造成很大的影响,针对此问题,提出PA-SSD(Parity-Aware Solid State Disk)控制器设计,从RAID5控制器得到校验信息的逻辑地址,在SSD控制器中设置一个缓存Pcache,暂存更新后的校验信息,并在SSD中将数据和校验分开布局,设置专门的区域存放校验信息。通过实验仿真测试,提出的方法能有效地减少校验信息对SSD的写操作,并且减少了SSD的擦除次数,提升了SSD阵列的性能和寿命。
