Hello, The answer is yes, as a quick search would have confirmed, for example: https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/3/html/administration_guide/osd-bluestore It's also been discussed here for years. ^.^ Christian On Mon, 1 Apr 2019 13:10:04 +0700 Igor Podlesny wrote: > It's wide known that some filesystems (well, ok -- 2 of them: ZFS and > Btrfs) detect bit rot on any read request, although, of course an > admin can initiate "whole platter" scrubbing. > > Before Bluestore CEPH could provide only "on demand" detection. I > don't take into consideration imaginary setups with Btrfs or ZFS > backed OSDs -- although Btrfs was supported it couldn't be trusted due > to being too quirky and ZFS would mean way higher overhead, resources > consumption; moreover, it conceptually doesn't fit well into CEPH's > paradigm. > So when scrub would find a mismatch that would trigger infamous HEALTH > ERR state and require manual tinkering to resolve (although, in > typical cases when 3 copies of placement group were used it seemed > more logical to autofix it -- at least most of its users would do same > choice in 99 % occurrences). > > Since Bluestore I'd expect bitrot detection to be made on any read > request as it's the case with Btrfs and ZFS. But expectations can be > wrong no matter how logically they might seem, and that's why I've > decide to clear it up. Can anyone tell for sure how does it work in > CEPH with Bluestore? > > If it's NOT the same as with those 2 CoW FSes and bit rot is detected > with scrubbing only how prone to data corruption / loss would be > > * 2 copies pools (2/1) > * erasure coded pools (say 2, 1) > > ? > > Let's consider replicated pool with 2/1 where both data instances are > up-to-date, and then one is found to be corrupted. Would be its csum > mismatch enough to be "cured" semi-automatically with ceph pg repair? > > What and how would happen in case erasure coded pool's data was found > to be damaged as well? > > -- > End of message. Next message? > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Rakuten Communications _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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