Self-Repairing Disk Arrays

Appeared in Proceedings of the Fifth International Workshop on Adaptive Self-tuning Computing Systems (ADAPT).

Abstract

As the prices of magnetic storage continue to decrease, the cost of replacing failed disks becomes increasingly dominated by the cost of the service call itself. We propose to eliminate these calls by building disk arrays that contain enough spare disks to operate without any human intervention during their whole lifetime. To evaluate the feasibility of this approach, we have simulated the behavior of two-dimensional disk arrays with n parity disks and n(n – 1)/2 data disks under realistic failure and repair assumptions. Our conclusion is that having n(n + 1)/2 spare disks is more than enough to achieve a 99.999 percent probability of not losing data over four years. We observe that the same objectives cannot be reached with RAID level 6 organizations and would require RAID stripes that could tolerate triple disk failures.

Publication date:
January 2015

Authors:
Jehan-François Pâris
Ahmed Amer
Darrell D. E. Long
Thomas Schwarz

Projects:
Archival Storage
Reliable Storage

Bibtex entry

@inproceedings{paris-adapt15,
  author       = {Jehan-François Pâris and Ahmed Amer and Darrell D. E. Long and Thomas Schwarz},
  title        = {Self-Repairing Disk Arrays},
  booktitle    = {Proceedings of the Fifth International Workshop on Adaptive Self-tuning Computing Systems (ADAPT)},
  month        = jan,
  year         = {2015},
}