1 / 8

Failure trends in a Large Disk Drive Population

This paper examines the failure trends of large disk drive populations, focusing on data collected 5-10 years ago when most drives were Parallel ATA, contrasting them with the currently prevalent SATA technology. It questions various assumptions related to power cycles, independent drive failures, and provides coarse measurements of annual failure rates (AFRs). The study also investigates utilization patterns, temperature variations, and empirical modeling. The discrepancies in findings compared to manufacturers and industry standards highlight the need for better statistical methods and empirical models to enhance reliability in different usage scenarios.

gunnar
Télécharger la présentation

Failure trends in a Large Disk Drive Population

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Shiva Srivastava and VaibhavRastogi offend Failure trends in a Large Disk Drive Population

  2. Relevance • Work conducted 5-10 years back • Disk drives have changed • All hard disks were Parallel ATA • Prevalent technology today is SATA • Some aspects not covered • Power cycles

  3. Assumptions • Drives fail independently of each other • Enables AFRs

  4. Coarse measurements • Definition of failures • Too coarse grained • When do the disks get replaced • Utilization • Weekly averages • Do not have anything better • Same for temperature

  5. Statistical correctness • What was the size of the fleet? • How does it compare with others • Patterns like those in Figure 3 may be random • Difference between 2 and 4 % is not much

  6. Usefulness • No good empirical model • Perhaps the measurements are too coarse • How am I supposed to use them? • Can they be different for different data centers, for different usage patterns?

  7. Improper presentation • Where is the control in Figure 8 and 11? • Why do the confidence levels decrease so much in Figure 11 • Shows there is a lot of variance? Why?

  8. Comparison with others • Your finding not corroborating manufacturers’ findings • Does it not go against you? • People have used large number of disks • How do you compare with them?

More Related