informare

Ross Lazarus, May 2016 This is an update to  http://bioinformare.blogspot.com.au/2016/02/survival-analysis-of-hard-disk-drive.html now that a dditional data for Q1 2016 has been released from https://www.backblaze.com/b2/hard-drive-test-data.html . I reran my scripts and got the plots shown below. Whole process only takes a few minutes. For me, the interesting thing is that so little really changes in the KM curves and statistics with 10% more data, suggesting that this statistical approach is reliable and robust, although in general we expect that more data provides better resolution.  The WD30-EFRX and WD10-EADS and drives are reordered in terms of failure risk with more data down near the middle of the pack, but the updated models KM curves otherwise suggest the same pattern of risk of failure over time. Hitachi and HGST have reversed their positions at the top of the manufacturer survival curves as a result of the additional data, but the other manufacturers remain...

Survival analysis of hard disk drive failure data. Ross Lazarus, February 2016 Executive Summary: Using a well established, objective analysis and data presentation method designed for right censored hard disk drive failure data provides insights which are not provided by simple descriptive statistics or charts. The Kaplan-Meier statistics and plots are recommended for routine use with hard drive failure data and their use is illustrated with 30M data points from the BackBlaze public data. Introduction: Hard disk drives are widely used for mass storage in servers, network attached storeage devices, laptops and desktop computers. Familiar and convenient as they are, these complex electro-mechanical devices are prone to sudden catastrophic failure, which can lead to very unpleasant consequences such as loss of data which was not securely backed up elsewhere. Selecting drive manufacturers and models for home or for commercial applications is complicated by the problem t...