Classifying Data to Reduce Long-Term Data Movement in Shingled Write Disks

Appeared in ACM Transactions on Storage 12(1).

Abstract

Shingled magnetic recording (SMR) is a means of increasing the density of hard drives that brings a new set of challenges. Due to the nature of SMR disks, updating in place is not an option. Holes left by invalidated data can only be filled if the entire band is reclaimed, and a poor band compaction algorithm could result in spending a lot of time moving blocks over the lifetime of the device. We propose using write frequency to separate blocks to reduce data movement and develop a band compaction algorithm that implements this heuristic. We demonstrate how our algorithm results in improved data management, resulting in an up to 45% reduction in required data movements when compared to naive approaches to band management.

Publication date:
February 2016

Authors:
Stephanie Jones
Ahmed Amer
Ethan L. Miller
Darrell D. E. Long
Rekha Pitchumani
Christina Strong

Projects:
Shingled Disk

Available media

Full paper text: PDF

Bibtex entry

@article{jones-tos16,
  author       = {Stephanie Jones and Ahmed Amer and Ethan L. Miller and Darrell D. E. Long and Rekha Pitchumani and Christina Strong},
  title        = {Classifying Data to Reduce Long-Term Data Movement in Shingled Write Disks},
  journal      = {ACM Transactions on Storage},
  volume       = {12},
  number       = {1},
  month        = feb,
  year         = {2016},
}