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23

Drive manufacturers specify the reliability of their products in terms of two related metrics: the annualized failure rate (AFR), which is the percentage of disk drives in a population that fail in a test scaled to a per year estimation; and the mean time to failure (MTTF). The AFR of a new product is typically estimated based on accelerated life and stress ...


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Unfortunately the MTBF isn't what most people think... It is not how long a an individual drive will last. Manufacturers expect their drives to last as long as the warranty, after that it really isn't their problem. Older electromagnetic platter hard drives will seize up after 10 or so years. Integrated circuits last an extremely long time, but other ...


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Here's a list of things to check. Are these HP disks? Are they generic disks installed in HP drive carriers? For the 500GB drive that appears to be 1TB, if it's HP-branded, HP replace older smaller capacities with larger disks, depending on product availability. 500GB SATA disks aren't made anymore, so that could be a reason. It is unlikely that your ...


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You should take images of all the RAID member drives with a tool like dd_rescue, and then assemble a RAID volume with these images. This way you don't put any extra stress to the failed hard disks, and you have the best chance to recover data.


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The photo looks like your system is an HP ProLiant DL360 G6 or G7 1U rackmount server. I saw your note about defective HP disks. I work with a considerable number of HP servers and haven't seen this as a widespread problem. I do think that you could provide more information about the Smart Array RAID controller's status during the system's POST process. ...


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They come from a statistical evaluation based on a small sample size and a short amount of time. There's really no universally agreed upon method or process so it's really just silly 'marketing'. This article may explain it a bit more. And Wikipedia has some formulas which might be what you're looking for? Essentially, for nearly everything (including ...


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Bad news about MTBF is that common evaluation metodics suppose evenly distributed write load among all NAND cells. But cells are grouped into the clusters and when one single cell fails - whole cluster is marked as dead and is replaced with new one from the reserve. Usually reserve is about 20% of the SSD volume. When reserve is exhausted whole SSD will be ...


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Q1: The order of [U] vs [U]. Why aren't they consistent along all the array? Is the first U /dev/sda or /dev/sdb? The order is based on the RaidDevice numbers. These are the numbers in the square brackets of the lines like this: md3 : active raid1 sdb4[2](S) sda4[0] 478713792 blocks [2/1] [U_] md2 : active raid1 sdb3[1] sda3[2](F) ...



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