Loading...

An I/O Cache Architecture in Open-Channel Solid-State Drives

Bazkhaneh, Amir Hossein | 2021

0 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 57193 (19)
  4. University: Sharif University of Technology
  5. Department: Computer Engineering
  6. Advisor(s): Asadi, Hossein; Sarbazi Azad, Hamid
  7. Abstract:
  8. Despite low time intervals between requests in many real-world workloads, the flash chip utilization remains very low, leaving the storage device mostly idle. This affects the performance of flash chips in Solid-State Drives (SSDs) and directly correlates with the diminished operational efficiency of these storage devices. Recent studies involve statistical analyses and workload behaviour modelling to maintain the operational efficiency of SSDs. However, due to the unavailability and non-disclosure of the internal control unit structure of conventional SSDs, namely Flash Translation Layer (FTL), the underlying assumptions of these methodologies are deviating from practical realities. Recently introduced SSDs, namely Open-Channel SSDs (OCSSDs), do not use built-in FTLs, enabling us to implement control functions on the host side. Notably, the principal factor constraining the performance of SSDs lies in the interference of access requests to the internal channels of the disk, a phenomenon yet unexplored in prior research. This thesis proposes a solution for managing access interference based on OCSSD technology. The proposed solution is integrated into the Logical to Physical (L2P) address mapping table. We have tested the proposed solution based on a custom simulator to evaluate its efficacy. A dedicated simulator tailored for OCSSDs, named HandiSim, has been fully designed, developed, and designated for post-processing our analysis in this research. Particularly, this simulator enables us to run concurrent multiple I/O threads, aligning with the parallel nature of OCSSDs. The implemented solution has been tested on the HandiSim platform. The outcomes of these tests show that workload characteristics such as I/O access rates, L2P address translation methodologies, and the degree of correlation between parallel workloads can affect the overall gained performance from OCSSDs
  9. Keywords:
  10. Input/Output Cache ; Open-Channel Solid-State Drives (SSDs) ; Data Storage ; Flash Translation Layer (FTL) ; Address Mapping ; Flash Chip

 Digital Object List

 Bookmark

No TOC