FluidSMR: Adaptive Management for Hybrid SMR Drives

2021 ◽  
Vol 17 (4) ◽  
pp. 1-30
Author(s):  
Fenggang Wu ◽  
Bingzhe Li ◽  
David H. C. Du
Keyword(s):  
Adaptive Management ◽  
Magnetic Recording ◽  
Disk Drive ◽  
Allocation Scheme ◽  
Performance Impact ◽  
Two Phase ◽  
Dynamic Data ◽  
Management Scheme ◽  
Shingled Magnetic Recording ◽  
Single Disk

Hybrid Shingled Magnetic Recording (H-SMR) drives are the most recently developed SMR drives, which allow dynamic conversion of the recording format between Conventional Magnetic Recording (CMR) and SMR on a single disk drive. We identify the unique opportunities of H-SMR drives to manage the tradeoffs between performance and capacity, including the possibility of adjusting the SMR area capacity based on storage usage and the flexibility of dynamic data swapping between the CMR area and SMR area. We design and implement FluidSMR, an adaptive management scheme for hybrid SMR Drives, to fully utilize H-SMR drives under different workloads and capacity usages. FluidSMR has a two-phase allocation scheme to support a growing usage of the H-SMR drive. The scheme can intelligently determine the sizes of the CMR and the SMR space in an H-SMR drive based on the dynamic changing of workloads. Moreover, FluidSMR uses a cache in the CMR region, managed by a proposed loop-back log policy, to reduce the overhead of updates to the SMR region. Evaluations using enterprise traces demonstrate that FluidSMR outperforms baseline schemes in various workloads by decreasing the average I/O latency and effectively reducing/controlling the performance impact of the format conversion between CMR and SMR.

Enabling Sequential-write-constrained B + -tree Index Scheme to Upgrade Shingled Magnetic Recording Storage Performance

2019 ◽  
Vol 18 (5s) ◽  
pp. 1-20
Author(s):  
Yu-Pei Liang ◽  
Tseng-Yi Chen ◽  
Yuan-Hao Chang ◽  
Shuo-Han Chen ◽  
Kam-Yiu Lam ◽  
...  
Keyword(s):  
Magnetic Recording ◽  
Storage Performance ◽  
Shingled Magnetic Recording ◽  
Tree Index

Head Instability Detection for Testing Process in Perpendicular Magnetic Recording System

2013 ◽  
Vol 770 ◽  
pp. 319-322 ◽  
Author(s):  
Piya Kovintavewat ◽  
Santi Koonkarnkhai ◽  
Aimamorn Suvichakorn
Keyword(s):  
Magnetic Recording ◽  
Signal To Noise Ratio ◽  
Disk Drive ◽  
Detection Algorithm ◽  
Recording System ◽  
High Signal ◽  
Signal To Noise ◽  
Perpendicular Magnetic Recording ◽  
Read Head ◽  
Pass Through

During hard disk drive (HDD) testing process, the magneto-resistive read (MR) head is analyzed and checked if the head is defective or not. Baseline popping (BLP) is one of the crucial problems caused by head instability, whose effect can distort the readback signal to the extent of causing possible sector read failure. Without BLP detection algorithm, the defective read head might pass through HDD assembling process, thus producing an unreliable HDD. This situation must be prevented so as to retain customer satisfaction. This paper proposes a simple (but efficient) BLP detection algorithm for perpendicular magnetic recording systems. Results show that the proposed algorithm outperforms the conventional one in terms of both the percentage of detection and the percentage of false alarm, when operating at high signal-to-noise ratio.

Signal Model for Shingled Magnetic Recording Based on Data Dependent Erase Band Analysis Under Track Squeeze

2013 ◽  
Vol 49 (2) ◽  
pp. 734-738 ◽  
Author(s):  
Euiseok Hwang ◽  
Ming Jin ◽  
Jongseung Park ◽  
Erich F. Haratsch ◽  
Ivana Djurdjevic ◽  
...  
Keyword(s):  
Magnetic Recording ◽  
Signal Model ◽  
Shingled Magnetic Recording

Influence of writing and reading intertrack interferences in terms of bit aspect ratio in shingled magnetic recording

2014 ◽  
Vol 115 (17) ◽  
pp. 17B729 ◽  
Author(s):  
Hirofumi Nobuhara ◽  
Yoshihiro Okamoto ◽  
Masato Yamashita ◽  
Yasuaki Nakamura ◽  
Hisashi Osawa ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Magnetic Recording ◽  
Shingled Magnetic Recording

Opposite Partial Response Filter for Shingled Magnetic Recording Systems

2020 ◽  
Vol 11 ◽  
pp. 1-4
Author(s):  
Chi Dinh Nguyen ◽  
Thu Phuong Nguyen ◽  
Sinh Cong Lam
Keyword(s):  
Partial Response ◽  
Magnetic Recording ◽  
Shingled Magnetic Recording

Skew angle effects in shingled magnetic recording system with double/triple reader head array

2014 ◽  
Vol 115 (17) ◽  
pp. 17B753 ◽  
Author(s):  
Moulay Rachid Elidrissi ◽  
Kheong Sann Chan ◽  
Simon Greaves ◽  
Yasushi Kanai ◽  
Hiroaki Muraoka
Keyword(s):  
Magnetic Recording ◽  
Recording System ◽  
Skew Angle ◽  
Shingled Magnetic Recording

Head Disk Spacing Effect on Heat Transfer in Heat Assisted Magnetic Recording

2017 ◽  
Author(s):  
Shaomin Xiong ◽  
Erhard Schreck ◽  
Sripathi Canchi
Keyword(s):  
Heat Transfer ◽  
Magnetic Recording ◽  
Spacing Effect ◽  
Disk Drive ◽  
Heat Assisted Magnetic Recording ◽  
Heating Source ◽  
Spacing Effects ◽  
Thermal Sensing ◽  
Transfer Mechanisms ◽  
Disk Spacing

Heat transfer at nanometer scale attracts a lot of interest from both academia and industries. The hard disk drive (HDD) industry cares about the heat transfer between the head and disk, as several heating and thermal sensing elements are integrated into the HDD system. Understanding the heat transfer mechanism and its dependency on spacing becomes very critical for heat assisted magnetic recording (HAMR). In this paper, we propose a new method to study the head disk spacing effects on heat transfer by introducing a small perturbation to the spacing while maintaining the heating source unchanged. The dependency of heat transfer on the nanoscale spacing provides insights to the understanding of heat transfer mechanisms inside the nanoscale gap.

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