The error is silently corrected and the correct data rewritten to the bad sector. There may be a slight latency increase on the read. The checksumming is implemented at the Bluestore layer, what you are storing makes no difference. On Fri, Mar 27, 2020 at 5:12 AM Priya Sehgal <priya.sehgal(a)gmail.com> wrote: > > Hi, > I am trying to find out whether Ceph has a method to detect silent > corruption such as bit rot. I came across this text in a book - "Mastering > Ceph : Infrastructure Storage Solution with the latest Ceph release" by > Nick Fisk - > > > Luminous release of Ceph employs ZFS-like ability to checksum data at every > read. BlueStore calculates and stores the crc32 checksum of any data that > is written. On each read request, BlueStore reads the checksum and compares > it with the data read from the device. If there is a mismatch, BlueStore > will report read error and repair damage. Ceph will then retry the read > from another OSD holding the object. > > I have two questions: > 1. If there is a mismatch will the ceph user (who initiated GET) receive > any error message and he has to retry OR will this error be auto-corrected > by Ceph and the data would be returned from the other OSD (user will never > know what went wrong underneath? > 2. Does this feature work for Multi-part upload objects also? > > -- > Regards, > Priya > _______________________________________________ > ceph-users mailing list -- ceph-users(a)ceph.io > To unsubscribe send an email to ceph-users-leave(a)ceph.io