Improving Hybrid FTL by Fully Exploiting Internal SSD Parallelism with Virtual Blocks

He, Dan; Wang, Fang; Jiang, Hong; Feng, Dan; Liu, Jing Ning; Tong, Wei; Zhang, Zheng

doi:10.1145/2677160

Cited by 8 publications

(6 citation statements)

References 24 publications

(28 reference statements)

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“…By erasing multiple blocks simultaneously, more space can be reclaimed during an erase operation. Our study is in line with VBP-FAST [17], I/O-parallelized GC [9], and IPPBE [15] in terms of leveraging parallelism inside SSDs. In contrast, we focus on utilizing the page-level parallelism.…”

Section: Related Worksupporting

confidence: 74%

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A Preliminary Study: Towards Parallel Garbage Collection for NAND Flash-Based SSDs

2020

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Section: Related Worksupporting

confidence: 74%

“…Leveraging parallelism inside SSDs: VBP-FAST [17] virtually makes a logical block span several channels. Therefore, data in a virtual block is actually placed on multiple physical blocks belonging to different channels, dies, and planes.…”

Section: Related Workmentioning

confidence: 99%

A Preliminary Study: Towards Parallel Garbage Collection for NAND Flash-Based SSDs

2020

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“…In VBP-FAST, the memory space is divided into VBlocks and PBlocks [25]. Each row of VBlocks is called a Big-Page.…”

Section: B the Previous Designated Ftlsmentioning

confidence: 99%

Improving Utilization and Life-Span in Parallel Aware MLC-Based SSD Using Virtual Blocks

Forouhar

Safaei

2020

IEEE Access

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FTL (Flash Translation Layer) is a memory block controller that manages the challenges of a data storage system based on flash memory technology. The design of internal parallelism in MLC-based SSDs with virtual blocks resulted in various challenges and due to the physical structure of flash memory cells based on MLC technology, it is possible to write a new page in a data block at the address after the last page is written. In parallel-based SSD design based on virtual blocks, some writes create unusable pages at the memory space, and these created holes reduce memory efficiency; consequently, it reduces the life-time of memory blocks by creating more operations, and accelerates garbage collection and merging operations. The proposed FTL offers three steps to address this constraint. Firstly, an idea was proposed to prevent costly transitions and to distribute data more evenly at memory blocks (wear leveling). Secondly, the unused holes created in virtual blocks became much fewer resulting in increased utilization of memory space. At last, a policy was proposed to prevent update blocks (log blocks) from being blocked and to postpone the merging and garbage collection by which the memory lifetime increases significantly. Simulation results showed that the number of unused erased pages and the number of extra write operations decreased up to 23% and 17%, respectively. In addition, the number of invalid released pages increased up to 21% in the proposed FTL, and the speed of I/O executions to 3%.INDEX TERMS Solid-state disk, MLC (multi-level cell), parallel virtual blocks, flash translation layer, life-span, memory utilization.

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“…In recent years, flash-based storage devices, solid-state drives (SSDs), are increasingly replacing hard-disk drives in modern storage systems [1], [12], [13]. Such flash-based storage devices have a cache layer, called a buffer cache, that buffers data [10], [11], [14], [15], [28]. When writing data to SSD, the data are cached in the buffer cache of SSD for a while.…”

Section: Introductionmentioning

confidence: 99%

Concurrent and Robust End-to-End Data Integrity Verification Scheme for Flash-Based Storage Devices

et al. 2022

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The amount of data generated by scientific applications on high-performance computing systems is growing at an ever-increasing pace. Most of the generated data are transferred to storage in remote systems for various purposes such as backup, replication, or analysis. To detect data corruption caused by network or storage failures during data transfer, the receiver system verifies data integrity by comparing the checksum of the data. However, the internal operation of the storage device is not sufficiently investigated in the existing end-to-end integrity verification techniques. In this paper, we propose a concurrent and reliable end-to-end data integrity verification scheme considering the internal operation of the storage devices for data transfer between high-performance computing systems with flash-based storage devices. To perform data integrity verification including data corruptions that occurred inside the storage devices, we control the order of I/O operations considering the internal operations of the storage devices. Also, to prove the effectiveness of the proposed scheme, we devise a prototype that injects faults on the specific layer of the storage stack and examines detection of faults. We parallelize checksum computation and overlap it with I/O operations to mitigate the overhead caused by I/O reordering. The experimental results show that the proposed scheme reduces the entire data transfer time by up to 62% compared with the existing schemes while ensuring robust data integrity. With the prototype implementation, our scheme detects failures on NAND flash memory inside storage devices that cannot be detected with the existing schemes.

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Improving Hybrid FTL by Fully Exploiting Internal SSD Parallelism with Virtual Blocks

Cited by 8 publications

References 24 publications

A Preliminary Study: Towards Parallel Garbage Collection for NAND Flash-Based SSDs

A Preliminary Study: Towards Parallel Garbage Collection for NAND Flash-Based SSDs

Improving Utilization and Life-Span in Parallel Aware MLC-Based SSD Using Virtual Blocks

Concurrent and Robust End-to-End Data Integrity Verification Scheme for Flash-Based Storage Devices

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