Reallocated Sectors Count Parameter for Analysing Hard Disk Drive Reliability

2019 ◽  
Vol 16 (12) ◽  
pp. 5298-5302
Author(s):  
Iskandar Nailovich Nasyrov ◽  
Ildar Iskandarovich Nasyrov ◽  
Rustam Iskandarovich Nasyrov ◽  
Bulat Askarovich Khairullin

The dependence of the SMART parameter 5 Reallocated sectors count value change on the operating time characterising the number of reallocated sectors is considered. This parameter is critical in the sense that if the attribute value increases, this may indicate deterioration in the state of the disk surface. The scientific task of the study is to establish relationships in the failed hard drives between the specified parameter and the values of other reliability parameters for information stores of various manufacturers. In the course of the study, the drives of the HGST, Hitachi, Samsung, ST, Toshiba, WDC trademarks operated in the Backblaze largest commercial data centre were analysed. The analysis revealed a relationship between the specified parameter and the parameters 1 Read error rate (frequency of errors (when reading data from the disk), the origin of which is due to the hardware of the disk), 196 Reallocation event count (number of reallocation operations), 197 Current pending sector count (number of sectors that are candidates for reallocation). It is shown that the nature of the change in the values of the considered parameters depends on the manufacturer of information storage devices. It is proposed to perform an individual assessment of the reliability of hard drives using the parameters identified as a result of the study.

2018 ◽  
Vol 7 (4.7) ◽  
pp. 200
Author(s):  
Iskandar N. Nasyrov ◽  
Ildar I. Nasyrov ◽  
Rustam I. Nasyrov ◽  
Bulat A. Khairullin

The problem of SMART-data ambiguity in different models of hard disk drives of the same manufacturers is considered. This circumstance creates obstacles for the use of SMART technology when assessing and predicting the reliability of storage devices. The scientific task of the work is to study the dependence of the hard disk failure probability on the reliability parameters values for each individual storage device of any model of any manufacturer. In the course of the study, two interrelated parameters were analyzed: “5 Reallocated sectors count” and “9 Power-on hours” (the number of hours spent in the on state). As a result of the analysis, two types of dependences were revealed: drooping and dome shaped. The first means the maximum failure frequency of information storage devices immediately after commissioning, the second - after a certain period of time, actually coinciding with the warranty period for the products (two years). With the help of clustering in plane according to the coordinates of the number of reallocated sectors and the time of operation, two different reasons for the failure of the drives were discovered: due to deterioration of the disk surface and due to errors in the positioning of the read / write heads. Based on the variety of types of causes and consequences of equipment failure, the task of individual assessment of an individual data storage device reliability is proposed to be solved using several parameters simultaneously.  


2019 ◽  
Vol 16 (12) ◽  
pp. 5303-5306
Author(s):  
Iskandar Nailovich Nasyrov ◽  
Ildar Iskandarovich Nasyrov ◽  
Rustam Iskandarovich Nasyrov ◽  
Bulat Askarovich Khairullin

The change of the SMART parameter 10 Spin retry count values depending on the operating time is considered; this parameter characterizes the number of repeated attempts to spin the disks up to operating speed if the first attempt was unsuccessful. This parameter is critical in the sense that if the value of the attribute increases, then the likelihood of malfunctions in the mechanical part of the hard disk drives is high. The scientific task of the study is to establish the relationship between this parameter in failed hard drives and the values of other reliability parameters for information stores from various manufacturers. In the course of the study, the drives of the HGST, Hitachi, Samsung, ST, Toshiba, WDC trademarks operated in the Backblaze largest commercial data centre were analysed. As a result of the analysis, the relationship between the specified parameter and such parameters as 3 Spin-up time (time of spinning the disk package from standstill to operating speed), 4 Start/stop count (counting the spindle start/stop cycles), 12 Power cycle count (number of full drive switching on/off cycles), 192 Power-off retract count (the number of shutdown cycles, including emergency), 193 Load cycle count (the number of magnetic head block moves in the parking zone/in working position cycles). It is shown that the nature of the change in the values of the considered parameters depends on the manufacturer of the hard drives. It is proposed to carry out an individual assessment of the information storage device rotation mechanism reliability using the parameters identified as a result of the study.


Author(s):  
Ronald Sloat ◽  
Jianbiao Pan

A non-contact angular measurement system for Pitch Static Attitude (PSA) and Roll Static Attitude (RSA) of hard disk drive sliders is designed and built. Real-time sampling at over 15 KHz is achieved with accuracy of +/−0.05 degrees over a range of approximately 2–3 degrees. Measuring the PSA and RSA is critical for hard drive manufacturers to control and improve the quality and reliability of hard drives. Although the hard drive industry is able to measure the PSA and RSA at the subassembly level at this time, there is no system available that is able to measure PSA/RSA at the final assembly level. This project has successfully demonstrated a methodology that the PSA/RSA can be reliably measured in-situ using a laser and position sensitive detector (PSD) technology. A prototype of the measurement system has been built. This device will allow a continuous measurement between the parked position on the ramp and the loading position just off of the disk surface. This measured data can be used to verify manufacturing processes and reliability data.


2020 ◽  
Vol 10 (3) ◽  
pp. 999
Author(s):  
Hyokyung Bahn ◽  
Kyungwoon Cho

Recently, non-volatile memory (NVM) has advanced as a fast storage medium, and legacy memory subsystems optimized for DRAM (dynamic random access memory) and HDD (hard disk drive) hierarchies need to be revisited. In this article, we explore the memory subsystems that use NVM as an underlying storage device and discuss the challenges and implications of such systems. As storage performance becomes close to DRAM performance, existing memory configurations and I/O (input/output) mechanisms should be reassessed. This article explores the performance of systems with NVM based storage emulated by the RAMDisk under various configurations. Through our measurement study, we make the following findings. (1) We can decrease the main memory size without performance penalties when NVM storage is adopted instead of HDD. (2) For buffer caching to be effective, judicious management techniques like admission control are necessary. (3) Prefetching is not effective in NVM storage. (4) The effect of synchronous I/O and direct I/O in NVM storage is less significant than that in HDD storage. (5) Performance degradation due to the contention of multi-threads is less severe in NVM based storage than in HDD. Based on these observations, we discuss a new PC configuration consisting of small memory and fast storage in comparison with a traditional PC consisting of large memory and slow storage. We show that this new memory-storage configuration can be an alternative solution for ever-growing memory demands and the limited density of DRAM memory. We anticipate that our results will provide directions in system software development in the presence of ever-faster storage devices.


2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Jungkyu Lee ◽  
Youfeng Zhang ◽  
Robert M. Crone ◽  
Narayanan Ramakrishnan ◽  
Andreas A. Polycarpou

Use of nanometer thin films has received significant attention in recent years because of their advantages in controlling friction and wear. There have been significant advances in applications such as magnetic storage devices, and there is a need to explore new materials and develop experimental and theoretical frameworks to better understand nanometer thick coating systems, especially wear characteristics. In this work, a finite element model is developed to simulate the sliding wear between the protruded pole tip in a recording head (modeled as submicrometer radius cylinder) and a rigid asperity on the disk surface. Wear is defined as plastically deformed asperity and material yielding. Parametric studies reveal the effect of the cylindrical asperity geometry, material properties, and contact severity on wear. An Archard-type wear model is proposed, where the wear coefficients are directly obtained through curve fitting of the finite element model, without the use of an empirical coefficient. Limitations of such a model are also discussed.


Author(s):  
Sarah Felix ◽  
Stanley Kon ◽  
Jianbin Nie ◽  
Roberto Horowitz

This paper describes the integration of thin film ZnO strain sensors onto hard disk drive suspensions for improved vibration suppression for tracking control. Sensor location was designed using an efficient optimization methodology based on linear quadratic gaussian (LQG) control. Sensors were fabricated directly onto steel wafers that were subsequently made into instrumented suspensions. Prototype instrumented suspensions were installed into commercial hard drives and tested. For the first time, a sensing signal was successfully obtained while the suspension was flying on a disk as in normal drive operation. Preliminary models were identified from experimental transfer functions. Nominal H2 control simulations demonstrated improved vibration suppression as a result of both the better resolution and higher sensing rate provided by the sensors.


2018 ◽  
Vol 83 (2) ◽  
pp. 213-220
Author(s):  
Sung Kim ◽  
Pankaj Attri ◽  
In Kim

In this paper, photosensitive materials for information storage devices are presented. The polymers were prepared using surface relief-grating (SRG) fabrication with a diode-pumped solid-state (DPSS) laser of 532 nm, and the diffraction efficiency (DE) of the polymers were assessed with a low-power DPSS laser at 633 nm. However, the diffraction efficiency of the azo-functionalized epoxy-based polymer was low, even after 15 min of exposure. To improve the efficiency and reduce the time it takes for the DE measurements of the photosensitive polymer, the polymer was combined ionic liquids (ILs). Various ILs, i.e., 1-methylimidazolium chloride ([Mim]Cl) from the imidazolium family of ILs and diethylammonium dihydrogen phosphate (DEAP), triethylammonium 4-aminotoluene-3-sulfonic acid (TASA) and tributylmethylammonium methyl sulphate (TBMS) from the ammonium family of ILs, were investigated. For the first time, it was observed that DE dramatically increased the DEAP?polymer mixture in 4 min compared to the polymer (alone) and other polymer?IL mixtures. Therefore, DEAP IL could help improve the efficiency of DE measurements in a shorter time.


Hard drives are the one which needs to be accessed in an efficient manner so that it is feasible to get better recital of the central processing unit. Now a day’s magnetic disks are capable of providing more input output bandwidth yet a huge amount of this bandwidth is lost due to the access time of the hard disk. This paper discusses an analysis of performance of various disk scheduling algorithms with their merits and demerits


Author(s):  
А.Н. Юров ◽  
Д.В. Цымбал

Предложена разработка цифрового макета изделия, который представляет собой компонент ЭВМ - импульсный блок питания. Производится анализ предполагаемых компонентов персонального компьютера, которые будут установлены в систему. При необходимости есть возможность выбора с добавлением новых компонентов в системный блок ЭВМ. После определения заданных компонентов ПК производится расчет мощности, которая нужна для получения стабильной работы системы в целом. По произведенным расчетам выполняется 3D-моделирование блока питания с разъемами для подключения материнской платы, видеокарты, а также прочих устройств, в том числе и накопителей информации. В работе исследованы вопросы по применению методов линейного программирования для решения поставленных задач в соответствии с исходными данными, а также подходы по получению 3D-модели источника питания с построенными трассами до разъемов подключения устройств и компонентов персонального компьютера. Кроме того, подготовлено программное обеспечение, в котором визуально представлен процесс построения сборочной модели БП согласно произведенным расчетам We propose the development of a digital model of the product, which is a computer component - a pulsed power supply. We carried out the analysis of the expected components of the personal computer that will be installed in the system. If necessary, there is a choice with the addition of new components to the system unit of the computer. After determining the specified PC components, the power is calculated, which is needed to obtain stable operation of the system as a whole. According to the calculations made, 3D-modeling of the power supply unit with connectors for connecting the motherboard, video card, as well as other devices, including information storage devices, is performed. The paper investigates the issues of using linear programming methods for solving the assigned tasks in accordance with the initial data, as well as approaches to obtaining a 3D model of a power supply with constructed routes to the connectors for connecting devices and components of a personal computer. In addition, we prepared the software, in which the process of building an assembly model of a power supply unit is visually presented according to the calculations


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Bahman A. Sassani (Sarrafpour) ◽  
Mohammed Alkorbi ◽  
Noreen Jamil ◽  
M. Asif Naeem ◽  
Farhaan Mirza

Sensitive data need to be protected from being stolen and read by unauthorized persons regardless of whether the data are stored in hard drives, flash memory, laptops, desktops, and other storage devices. In an enterprise environment where sensitive data is stored on storage devices, such as financial or military data, encryption is used in the storage device to ensure data confidentiality. Nowadays, the SSD-based NAND storage devices are favored over HDD and SSHD to store data because they offer increased performance and reduced access latency to the client. In this paper, the performance of different symmetric encryption algorithms is evaluated on HDD, SSHD, and SSD-based NAND MLC flash memory using two different storage encryption software. Based on the experiments we carried out, Advanced Encryption Standard (AES) algorithm on HDD outperforms Serpent and Twofish algorithms in terms of random read speed and write speed (both sequentially and randomly), whereas Twofish algorithm is slightly faster than AES in sequential reading on SSHD and SSD-based NAND MLC flash memory. By conducting full range of evaluative tests across HDD, SSHD, and SSD, our experimental results can give better idea for the storage consumers to determine which kind of storage device and encryption algorithm is suitable for their purposes. This will give them an opportunity to continuously achieve the best performance of the storage device and secure their sensitive data.


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