• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.81-87
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• 2002

본 논문은 RAID 시스템의 몇 가지 구성에 대해 시뮬레이션을 통해 그 성능을 분석한다. 대용량의 RAID를 구성하기 위해서는 다수의 디스크가 필요한데 반해, 하나의 PCI의 버스에 연결될 수 있는 장치의 개수 제한되어 있어 이 경우 확장 PCI 버스가 필요하다. 본 논문에서는 RAID 시스템의 하드웨어 구조, 특히 각 구성요소를 연결하는 PCI버스의 부하에 초점을 맞춘다. 버스 트랜잭션을 세 가지로 분류하고, 각각의 경우를 분석하고 평가한다. 이 분석으로부터 RAID 시스템의 두 가지 구조에 대해 성능을 계산하고 시뮬레이션 한 결과를 비교한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.158-163
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• 2003

When the number of disks array systems that contain multiple disk drives, system performance is limited by a bottleneck at a centralized controller at a communication path than uses a bus. A redundant array of inexpensive disks(RAID) consists of many disks to enable high performance and large capacity. We evaluate a scalable architecture called Autonomous network, in which the controller functions are distributed to all disk drives and each disk has autonomy in processing its tasks. Disks drives enable better scalability and more effective utilization of system resources than with a hierarchical system. Autonomous network provided high read/write performance throughput in proportion to the number of disks.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.105-113
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• 2013

RAID systems have been widely used by connecting several disks in parallel structure. to resolve the delay and bottleneck of data I/O. Recently, SSD based RAID systems are emerging since SSDs have better I/O performance than HDD. However, endurance and power consumption problems due to frequent write operation in SSD based RAID system should be resolved. In this paper, we propose a de-duplication method of parity disk in SSD based RAID system with expensive update cost. The proposed method segments chunk of parity data into small pieces and removes duplicate data, therefore, it can reduce wear-leveling and power consumption by decreasing write operation for duplicated parity data. Experimental results show that bit update rate of the proposed method is 16% in total disk, 31% in parity disk less than that of existing method in RAID-6 system using EVENODD erasure code, and the power consumption of the proposed method is 30% less than that of existing method. Besides the proposed method is 12% in total disk, 32% in parity disk less than that of existing method in RAID-5 system, and the power consumption of the proposed method is 36% less than that of existing method.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.365-368
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• 2002

본 논문에서는 SANtopiaVM의 데이터 가용성 및 성능을 고려한 에러 핸들링 정책을 제안한다. 제안하는 에러 핸들링 정책은 RAID1과 RAID5에 대한 정책으로 추분하며 에러 발생시의 복구를 위하여 RAID1에서는 FBB(Failed Block Bitmap)라는 비트맵을 추가하여 데이터의 일관성을 유지하고 디스크의 복구 시에는 저기 연산에 대한 부하 분산 및 복구 비용을 감소시키는 쓰기 연산을 제안함으로서 에러 핸들링 시에 입출력 비용을 줄인다. RAID5에서는 추가적인 여분 디스크를 사용한 Sparing Disk 기법을 제안함으로서 디스크 에러 모드에서도 정상 모드의 성능에 근접하는 입출력 성능을 보장하며 빠른 디스크 복구를 지원한다. 제안하는 에러 핸들링 정책은 SANtopiaVM RAID의 오류 발생시, 시스템 성능의 급격한 저하를 완화할 수 있으며 에러로부터 빠른 복구를 지원함으로서 데이터에 대한 효율적인 고 가용성의 특징을 제공한다.

• The KIPS Transactions:PartA
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• v.10A no.2
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• pp.123-130
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• 2003

This paper presents a new striped checkpointing scheme for serverless cluster computers, where the local disks are attached to the cluster nodes collectively form a distributed RAID with a single I/O space. Striping enables parallel I/O on the distributed disks and staggering avoids network bottleneck in the distributed RAID. We demonstrate how to reduce the checkpointing overhead and increase the availability by striping and staggering dynamically for communication intensive applications. Linpack HPC Benchamark and MPI programs are applied to these checkpointing schemes for performance evaluation on the 16-nodes cluster system. Benchmark results prove the benefits of the striped checkpointing scheme compare to the existing schemes, and these results are useful to design the efficient checkpointing scheme for fast rollback recovery from any single node failure in a cluster system.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.77-81
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• 2001

In this paper, a RAID system is modeled and simulated by using the DEVS formalism. The RA[D system interacts with a host system by using the high-speed Fibre channel protocol and stores input data in an array of IDE disks. The DEVS formalism specifies discrete event systems in a hierarchical, modular manner. The RAID system model is composed of three units: primary-PCI unit, secondary-PCI unit and CPU unit. The primary-PCI unit interfaces with the host system and caches I/O data. The secondary-PCI unit includes disks. The CPU unit controls overall system. The control algorithm of CPU and PCI transactions are analyzed and modeled. From an analysis of simulation events, we can conclude that the proposed model satisfies given requirements.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.6
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• pp.47-56
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• 2010

HDD-based RAIDs have been used in high-capacity storage systems for traditional data server. However, their data reliability are relatively low and they consume lots of power since hard disk drive is weak on shock and its power consumption is high due to frequent spindle motor operation. Therefore, this paper presents new SSD based RAID system architecture using various erasure codes. The proposed methode applys Reed-Solomon, EVENODD, and Liberation coding schemes onto file system level and device driver level, respectively. Besides, it uses data allocation method to minimize the side effect of reducing the lifespan of SSD. Detail experimental results show that Liberation code increase wear-leveling rates of SSD based RAID-6 more than other codes. The SSD based RAID system applying erasure codes at the device driver level shows better performance than that at the file system level. I/O performance of RAID-6 system using SSD is 4.5%~8.5% higher than that of using HDD and the power consumption of the RAID system using SSD is 18%~40% less than that of using HDD.

• Journal of Digital Forensics
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• v.12 no.3
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• pp.27-38
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• 2018

Recently, as the amount of digital data rapidly increases, a large storage space is required. RAID is a system that can manage large capacity storage space. Storage space provided by Windows is a type of software RAID. Storage space has been supported since Windows 8, Windows Server 2012, and no analysis has been done on the functionality. To analyze system using storage space, analysis of storage space function and reconstruction method of virtual disk should be studied. In this paper, we briefly describe the layout of existing RAID, explain the layout and metadata of storage space of software RAID, present reconstruction method of virtual disk by disk layout, and verify the result through experiments.

• Journal of the Korea Computer Industry Society
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• v.10 no.5
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• pp.193-200
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• 2009

In this paper, the raid and fire preventable system using Zibee module with IEEE 802.15.4 wireless communication standard and multi-sensor was developed displaying raid and firing condition with wireless network. The raid preventable system is designed using a ultrasonhe waves sensor and infrared sensor. The fire preventable system is designed using a thermistor. The datas for raid and firing condition are communicated from enddevice to coordinator with wireless network and are displayed on PC monitor.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.10
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• pp.1026-1031
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• 2008

This paper describes the establishment result of high speed data receiving and archiving system(HDRAS) using data receiving card(DRC) developped by SaTReC and low cost RAID(Redundant Array of Independent Disks) storage instead of expensive enterprise RAID storage. We used three S-ATA2 type hard disks and performance test program developped by SaTReC to receive and save data at 350Mbps. Finally, we verified that the HDRAS using low cost RAID storage has a capacity to process received data at 79MB/s(632Mbps).