On Thu, Mar 29, 2018 at 5:09 PM, Ronny Aasen <ronny+ceph-users@xxxxxxxx> wrote: > On 29.03.2018 20:02, Alex Gorbachev wrote: >> >> w Luminous 12.2.4 cluster with Bluestore, I see a good deal >> of scrub and deep scrub operations. Tried to find a reference, but >> nothing obvious out there - was it not supposed to not need scrubbing >> any more due to CRC checks? > > > crc gives you checks as you read data. iow you do not give corrupt data to > clients, while thinking it is ok data. > scrubs periodically checks your data for corruption, by reading it and > comparing it to crc and the other replicas. this protects against bitrot > [1] > crc also helps the system to know what object is good and what object is bad > during scrub. > > crc is not a replacement for scrub, but a compliment. it improves the > quality of the data you provide to clients, and it makes it easier for scrub > to detect errors. > > > kind regards > Ronny Aasen > > [ 1] https://en.wikipedia.org/wiki/Data_degradation Thank you Ronny, this explains the scrub states. The deep scrubs did affect the system performance, apparently, but a setting of osd scrub sleep > 0.1 does appear to help -- Alex Gorbachev Storcium > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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