플래시 메모리 시스템을 위한 신뢰성 있는 RAID 기법
A Reliable RAID Technique for Flash Memory System
- 주제(키워드) 플래시메모리시스템 , 신뢰성
- 발행기관 아주대학교
- 지도교수 정태선
- 발행년도 2016
- 학위수여년월 2016. 2
- 학위명 석사
- 학과 및 전공 일반대학원 컴퓨터공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000021400
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Flash memory features low power consumption, light weight, and fast speed. Because of its characteristics, flash memory is widely used in various devices for consumers, such as a smart phone, a smart pad, a digital camera, a desktop, and a large scale data center, etc. However, flash memory has a limit of write/erase times problem and high error rate problem. These problems cause low reliability of SSD. To increase its reliability, traditionally error correction codes (ECCs) are used. The Redundancy Array of Inexpensive Disk (RAID) is widely used to enhance both reliability and performance of SSD by redundant data across multiple disks. When the RAID technique is used in SSD, update operations in the parity disk occur more frequent than other disks. To solve this problem, I propose the new RAID technique for SSD. The proposedFlash memory features low power consumption, light weight, and fast speed. Because of its characteristics, flash memory is widely used in various devices for consumers, such as a smart phone, a smart pad, a digital camera, a desktop, and a large scale data center, etc. However, flash memory has a limit of write/erase times problem and high error rate problem. These problems cause low reliability of SSD. To increase its reliability, traditionally error correction codes (ECCs) are used. The Redundancy Array of Inexpensive Disk (RAID) is widely used to enhance both reliability and performance of SSD by redundant data across multiple disks. When the RAID technique is used in SSD, update operations in the parity disk occur more frequent than other disks. To solve this problem, I propose the new RAID technique for SSD. The proposed RAID technique uses the uneven parity distribution without any disk replacement. The reliability of the proposed RAID technique is also analyzed with discrete time markov chain. Consequently, the proposed SSD RAID scheme improves reliability. RAID technique uses the uneven parity distribution without any disk replacement. The reliability of the proposed RAID technique is also analyzed with discrete time markov chain. Consequently, the proposed SSD RAID scheme improves reliability.
more목차
1. Introduction 1
2. Backgroung Information & Related Works 4
2.1 Flash memory 4
2.2 FTL (Flash translation layer) 6
2.3 Redundancy Array of Inexpensive Disk (RAID) 8
2.3.1 RAID 0 8
2.3.2 RAID 4 8
2.4 RAID technique for SSD 10
2.4.1 RAID 5 10
2.4.2 Differential RAID 11
2.5 Reliability Analysis 15
2.6 Related works 18
3. Uneven parity distribution without replacement 19
3.1 system model 19
3.2 SSD RAID formulations 22
3.3 Analysis of RAID reliability 23
4. Reliability evaluation 26
5. Conclusion 31
Reference 32
