Patrones De Fallo En Discos Duros De Computadoras (Ingles)

Appears in the Proceedings of the 5th USENIX Conference on File and Storage Technologies (FAST’07), February 2007

Failure Trends in a Large Disk Drive Population
Eduardo Pinheiro, Wolf-Dietrich Weber and Luiz Andr´ Barroso e Google Inc. 1600 Amphitheatre Pkwy Mountain View, CA 94043 {edpin,wolf,luiz}@google.com

Abstract
It is estimated that over 90% of all new information produced in theworld is being stored on magnetic media, most of it on hard disk drives. Despite their importance, there is relatively little published work on the failure patterns of disk drives, and the key factors that affect their lifetime. Most available data are either based on extrapolation from accelerated aging experiments or from relatively modest sized field studies. Moreover, larger population studiesrarely have the infrastructure in place to collect health signals from components in operation, which is critical information for detailed failure analysis. We present data collected from detailed observations of a large disk drive population in a production Internet services deployment. The population observed is many times larger than that of previous studies. In addition to presenting failurestatistics, we analyze the correlation between failures and several parameters generally believed to impact longevity. Our analysis identifies several parameters from the drive’s self monitoring facility (SMART) that correlate highly with failures. Despite this high correlation, we conclude that models based on SMART parameters alone are unlikely to be useful for predicting individual drivefailures. Surprisingly, we found that temperature and activity levels were much less correlated with drive failures than previously reported.

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Introduction

The tremendous advances in low-cost, high-capacity magnetic disk drives have been among the key factors helping establish a modern society that is deeply reliant on information technology. High-volume, consumergrade disk drives have becomesuch a successful product that their deployments range from home computers and appliances to large-scale server farms. In 2002, for example, it was estimated that over 90% of all new information produced was stored on magnetic media, most of it being hard disk drives [12]. It is therefore critical to improve our understanding of how robust these components are and what main factors are associatedwith failures. Such understanding can be particularly useful

for guiding the design of storage systems as well as devising deployment and maintenance strategies. Despite the importance of the subject, there are very few published studies on failure characteristics of disk drives. Most of the available information comes from the disk manufacturers themselves [2]. Their data are typically based onextrapolation from accelerated life test data of small populations or from returned unit databases. Accelerated life tests, although useful in providing insight into how some environmental factors can affect disk drive lifetime, have been known to be poor predictors of actual failure rates as seen by customers in the field [7]. Statistics from returned units are typically based on much largerpopulations, but since there is little or no visibility into the deployment characteristics, the analysis lacks valuable insight into what actually happened to the drive during operation. In addition, since units are typically returned during the warranty period (often three years or less), manufacturers’ databases may not be as helpful for the study of long-term effects. A few recent studies have shedsome light on field failure behavior of disk drives [6, 7, 9, 16, 17, 19, 20]. However, these studies have either reported on relatively modest populations or did not monitor the disks closely enough during deployment to provide insights into the factors that might be associated with failures. Disk drives are generally very reliable but they are also very complex components. This combination...