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Lible failures readwrite errors one byte in 1013 31

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Unformatted text preview: it does fail, if rarely   big failures (drive dies; MTBF ~3 years) –  if you have 100K drives and MTBF is 3 years, that’s 1 “big failure” every 15 minutes!   lible failures (read/write errors, one byte in 1013) 31 May 2012 Disks and File Systems 3 University of Washington A trip down memory lane … IBM 2314 About the size of 6 refrigerators 8 x 29MB (M!) Required similar ­ sized air cond.! .01% (not 1% – .01%!) the capacity of this $100 4”x6”x1” item 31 May 2012 Disks and File Systems 4 University of Washington Disk trends   Disk capacity, 1975 ­1989           Disk capacity, 1990 ­recently         31 May 2012 doubled every 3+ years 25% improvement each year factor of 10 every decade SKll exponenKal, but far less rapid than processor performance doubling every 12 months 100% improvement each year factor of 1000 every decade Capacity growth 10x as fast as processor performance! Disks and File Systems 5 University of Washington Disk Trends     Only a few years ago, we purchased disks by the megabyte (and it hurt!) Today, 1 GB (a billion bytes) costs $1 $0.50 $0.05 from Dell (except you have to buy in increments of 40 80 250 1000 GB)   => 1 TB costs $1K $500 $100, 1 PB costs $1M $500K $100K  ...
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