scholarly journals An Empirical Evaluation of NVM-Aware File Systems on Intel Optane DC Persistent Memory Modules

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1977
Author(s):  
Guangyu Zhu ◽  
Jaehyun Han ◽  
Sangjin Lee ◽  
Yongseok Son
Keyword(s):  
Data Management ◽  
Empirical Evaluation ◽  
File Systems ◽  
Data Management System ◽  
Nand Flash ◽  
Storage Devices ◽  
Persistent Memory ◽  
Memory Modules ◽  
And Performance ◽  
And Storage

The emergence of non-volatile memories (NVM) brings new opportunities and challenges to data management system design. As an important part of the data management systems, several new file systems are developed to take advantage of the characteristics of NVM. However, these NVM-aware file systems are usually designed and evaluated based on simulations or emulations. In order to explore the performance and characteristics of these file systems on real hardware, in this article, we provide an empirical evaluation of NVM-aware file systems on the first commercially available byte-addressable NVM (i.e., the Intel Optane DC Persistent Memory Module (DCPMM)). First, to compare the performance difference between traditional file systems and NVM-aware file systems, we evaluate the performance of Ext4, XFS, F2FS, Ext4-DAX, XFS-DAX, and NOVA file systems on DCPMMs. To compare DCPMMs with other secondary storage devices, we also conduct the same evaluations on Optane SSDs and NAND-flash SSDs. Second, we observe how remote NUMA node access and device mapper striping affect the performance of DCPMMs. Finally, we evaluate the performance of the database (i.e., MySQL) on DCPMMs with Ext4 and Ext4-DAX file systems. We summarize several observations from the evaluation results and performance analysis. We anticipate that these observations will provide implications for various memory and storage systems.

Octopus + : An RDMA-Enabled Distributed Persistent Memory File System

2021 ◽  
Vol 17 (3) ◽  
pp. 1-25
Author(s):  
Bohong Zhu ◽  
Youmin Chen ◽  
Qing Wang ◽  
Youyou Lu ◽  
Jiwu Shu
Keyword(s):  
High Speed ◽  
High Performance ◽  
File System ◽  
Direct Memory Access ◽  
File Systems ◽  
Distributed File Systems ◽  
Persistent Memory ◽  
Memory Modules ◽  
Non Volatile Memory ◽  
Volatile Memory

Non-volatile memory and remote direct memory access (RDMA) provide extremely high performance in storage and network hardware. However, existing distributed file systems strictly isolate file system and network layers, and the heavy layered software designs leave high-speed hardware under-exploited. In this article, we propose an RDMA-enabled distributed persistent memory file system, Octopus + , to redesign file system internal mechanisms by closely coupling non-volatile memory and RDMA features. For data operations, Octopus + directly accesses a shared persistent memory pool to reduce memory copying overhead, and actively fetches and pushes data all in clients to rebalance the load between the server and network. For metadata operations, Octopus + introduces self-identified remote procedure calls for immediate notification between file systems and networking, and an efficient distributed transaction mechanism for consistency. Octopus + is enabled with replication feature to provide better availability. Evaluations on Intel Optane DC Persistent Memory Modules show that Octopus + achieves nearly the raw bandwidth for large I/Os and orders of magnitude better performance than existing distributed file systems.

scholarly journals Features of Organization and Application of Active Balancing Cells with Extended Triggering Range of Shunt Circuits Keys in Ionistor Modules and Storage Devices of Joint-Stock Company “Elecond”

2021 ◽  
Vol 24 (3) ◽  
pp. 68-77
Author(s):  
T.G. Chikurov ◽  
M.V. Kibardin ◽  
S.L. Shirokih
Keyword(s):  
Storage Device ◽  
Joint Stock Company ◽  
Stock Company ◽  
Voltage Level ◽  
Storage Devices ◽  
Active Balancing ◽  
And Performance ◽  
Comparison Circuit ◽  
And Storage ◽  
Shunt Circuit

The solution of the problem of the deficit of voltage level for the complete unlocking of MOSFETs used as keys in the shunt circuits of the cells of the active balancing of ionistor storage devices is given. In particular, a revision of the widespread two-pole circuit of the active balancing cell of the ionistor consisting of a comparison circuit and a shunt circuit with a key on the MOSFET is presented. The relevance of the problem is confirmed by the results of the analysis of the characteristics of the key MOSFETs at the level of the unlocking voltage of 2.5...2.7 V from the output of the comparison circuit. It is shown that this voltage is not sufficient to provide the channel resistance corresponding to a fully open transistor and the flow of the specified shunt currents in the entire range of external influencing factors (VVF), especially when exposed to a reduced temperature from plus 15 to minus 60 °C. The solution presented in the paper for finalizing the circuit of the active balancing cell is that voltage boost circuits are introduced between the comparison node and the shunt circuit. Their use allows you to increase the voltage at the gate of the key MOSFET by two, three, four, etc. times, which ensures the reliable operation of the shunt circuit key for different shunt currents. A special feature of the developed cell circuits is the three-pole switching, in which an additional output is connected to the adjacent ionistor cell. This method of switching on the developed active balancing cells provides doubling of the unlocking voltage on the gate and is sufficient for reliable unlocking of the key on the MOSFET at all shunt currents at the level of the charging voltage of the ionistors in the storage device 2.5...2.7 V. For shunt currents of the order of tens of amperes, it is shown that it is necessary to switch to a quasi-four-pole switching of the developed active balancing cell due to the separation of the supply power circuits (measuring circuits) of the comparison circuit and the power buses of the level-up circuit with the shunt circuit. The methods of switching on the developed cells that allow multiplying the unlocking voltage at the gate of the key MOSFET by three, four or more times are shown. The schemes and criteria for the necessity of applying such inclusion are given. Practical testing of the developed three-pole and quasi-four-pole active balancing cells, carried out on the ionistor NEE of JSC “Elecond”, showed satisfactory stability and performance under the influence of the entire set of VVF.

MEDIC: An on Site Designed Data Management System for Cardiology

1979 ◽  
Vol 18 (04) ◽  
pp. 199-202 ◽  
Author(s):  
F. Lustman ◽  
P. Lanthier ◽  
D. Charbonneau
Keyword(s):  
Data Management ◽  
Management System ◽  
Selection Process ◽  
Low Cost ◽  
Database Management System ◽  
Data Management System ◽  
Data Quality Control ◽  
Data Definition ◽  
And Performance ◽  
Data Independence

A patient-oriented data management system is described. The environment was cardiology with a heavy emphasis on research and the MEDIC system was designed to meet the day to day program needs. The data are organized in speciality files with dynamic patient records composed of subrecords of different types. The schema is described by a data definition language. Application packages include data quality control, medical reporting and general inquiry.After five years of extensive use in various clinical applications, its utility has been assessed as well as its low cost. The disadvantages, the main being the multifile structure, can now be stated as its advantages, like data independence and performance increase. Although the system is now partially outdated, the experience acquired with its use becomes very helpful in the selection process of the future database management system.

scholarly journals The Belle II Raw Data Management System

2020 ◽  
Vol 245 ◽  
pp. 04005 ◽  
Author(s):  
Michel Hernández Villanueva ◽  
Ikuo Ueda
Keyword(s):  
Data Management ◽  
Management System ◽  
Computing System ◽  
Data Management System ◽  
Current Status ◽  
Distributed Data ◽  
Data Set ◽  
Raw Data ◽  
Belle Ii ◽  
And Performance

The Belle II experiment, a major upgrade of the previous e+e− asymmetric collider experiment Belle, is expected to produce tens of petabytes of data per year due to the luminosity increase from the upgraded SuperKEKB accelerator. The distributed computing system of the Belle II experiment plays a key role, storing and distributing data in a reliable way to be easily accessed and analyzed by more than 1000 collaborators. In particular, the Belle II Raw Data Management system has been developed with an aim to upload output files onto grid storage, register them into the file and metadata catalogs, and make two replicas of the full raw data set using the Belle II Distributed Data Management system. It has been implemented as an extension of DIRAC (Distributed Infrastructure with Remote Agent Control) and consists of a database, services, client and monitoring tools, and several agents that treat the data automatically. The first year of data taken with the Belle II full detector has been managed by the Belle II Raw Data Management system successfully. The design, current status, and performance are presented. Prospects for improvements towards the full luminosity data taking are also reviewed.

scholarly journals Development of the JUNO Conditions Data Management System

2020 ◽  
Vol 245 ◽  
pp. 04030
Author(s):  
Xingtao Huang
Keyword(s):  
Data Management ◽  
Management System ◽  
Liquid Scintillator ◽  
Data Management System ◽  
Mass Hierarchy ◽  
Neutrino Mass Hierarchy ◽  
Web Interfaces ◽  
The Status ◽  
And Performance ◽  
Treat All

The Jiangmen Underground Neutrino Observatory (JUNO) experiment is designed to determine the neutrino mass hierarchy and precisely measure oscillation parameters with an unprecedented energy resolution of 3% at 1 MeV. It is composed of a 20 kton liquid scintillator central detector equipped with 18000 20-inch PMTs and 25000 3-inch PMTs, a water pool with 2000 20-inch PMTs, and a top tracker. Conditions data, coming from calibration and detector monitoring, are heterogeneous, different type of conditions data has different write rates, data format and data volume. JUNO conditions data management system (JCDMS) is developed to homogeneously treat all these heterogeneous conditions data in order to provide easy management and convenient access with both Restful API and web interfaces, support good scalability and maintenance for long time running. The paper describes the status and development of JCDMS including the data model, workflows, interfaces, data caching and performance of the system.

scholarly journals Battery Characterization and Dimensioning Approaches for Micro-Grid Systems

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1305 ◽  
Author(s):  
Sofia Boulmrharj ◽  
Youssef NaitMalek ◽  
Abdellatif Elmouatamid ◽  
Mohamed Bakhouya ◽  
Radouane Ouladsine ◽  
...  
Keyword(s):  
Energy Management ◽  
Energy Production ◽  
Production Systems ◽  
Renewable Energy Sources ◽  
Optimum Size ◽  
Grid Systems ◽  
Storage Devices ◽  
Micro Grid ◽  
And Performance ◽  
And Storage

Micro-Grid (MG) systems have been extensively studied and deployed to lower the power consumption while reducing the greenhouse gas emissions. Although, the challenge with Renewable Energy Sources (RES) is their uncertain and intermittent nature, things that led the researchers to think about integrating storage devices, especially batteries, into MG systems. The main aim is to store the excess of produced energy for further usage when not enough energy is available. Nevertheless, batteries modeling and characterization is mandatory to identify their parameters and study their performance within MG systems. Moreover, in order to continuously supply electricity to the building, it is required to figure out the optimum size of energy production systems and storage devices. This paper introduces a methodology for MG modeling and performance evaluation. Its main contribution is twofold, i) battery’s parameters identification, and ii) modeling and dimensioning method for both standalone and MG systems. An instrumentation platform, composed of recent sensing and actuating equipment, for MG energy management and battery characterization is developed. Simulation and experimental results show the effectiveness of the proposed methodology.

Sign in / Sign up

Export Citation Format

Share Document