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SSD reliability in the real world: Google's experience

http://www.zdnet.com/article/ssd-reliability-in-the-real-world-googles-experience/ SSDs are a new phenomenon in the datacenter. We have theories about how they should perform, but until now, little data . That's just changed. The FAST 2016 paper Flash Reliability in Production: The Expected and the Unexpected, (the paper is not available online until Friday) by Professor Bianca Schroeder of the University of Toronto, and Raghav Lagisetty and Arif Merchant of Google, covers: Millions of drive days over 6 years 10 different drive models 3 different flash types: MLC, eMLC and SLC Enterprise and consumer drives Key conclusions Ignore Uncorrectable Bit Error Rate (UBER) specs. A meaningless number. Good news: Raw Bit Error Rate (RBER) increases slower than expected from wearout and is not correlated with UBER or other failures. High-end SLC drives are no more reliable that MLC drives. Bad news: SSDs fail at a lower rate than disks, but UBER rate is higher (see be...
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Why there is no Hitchhiker’s Guide to Mathematics for Programmers

http://jeremykun.com/2013/02/08/why-there-is-no-hitchhikers-guide-to-mathematics-for-programmers/ Why there is no Hitchhiker’s Guide to Mathematics for Programmers Posted on February 8, 2013 by j2kun For those who aren’t regular readers: as a followup to this post, there are four posts detailing the basic four methods of proof, with intentions to detail some more advanced proof techniques in the future. You can find them on this blog’s primers page . Do you really want to get better at mathematics? Remember when you first learned how to program? I do. I spent two years experimenting with Java programs on my own in high school . Those two years collectively contain the worst and most embarrassing code I have ever written. My programs absolutely reeked of programming no-nos . Hundred-line functions and even thousand-line classes, magic numbers, unreachable blocks of code, ridiculous code comments, a complete disregard for sensible object orientation, neglige...
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