Le 22/12/2015 17:36, Tyler Bishop a écrit : > Write endurance is kinda bullshit. > > We have crucial 960gb drives storing data and we've only managed to take 2% off the drives life in the period of a year and hundreds of tb written weekly. This is not really helpful without more context. This would help if you stated: * the exact model including the firmware version, * how many SSDs are used to handle these hundreds of TB written weekly (if you use 1000 SSDs your numbers don't mean the same thing that if you use only 10 of them on your cluster), * if you use them as journals, storage or both, * if it is 200TB or 900TB weekly, * if you include the replication size in the amount written (and/or the double writes if you use them for both journal and store). If you imply that the 2% is below what you would expect according to the total TBW specified for your model you clearly have a problem and I wouldn't trust these drives: the manufacturer is lying to you one way or another. If it underestimates the TBW then fine (but why would it look bad on purpose ?) but if it overestimates the reported life expectancy because of a bug you can expect a catastrophic failure if you hit the real limit before replacing the SSDs. One year is a bit short to have a real experience on endurance too: some consumer-level drives (Samsung 850 PRO IIRC) have been known to fail early (far before their expected life felled to 0 according to their SMART attributes), although I don't remember seeing any reports for Crucial SSD yet. If you replaced Crucial 960gb by 850 Pro in your statement I'd clearly worry about your cluster failing badly in the short future. Without knowing more about the exact model you use and the real numbers for your cluster I don't know what could happen. Lionel _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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