Hi Stefan, Hi Manuel, thanks for your quick advices. In fact, since i set "ceph config set osd bluefs_buffered_io true", the problems disappeared. We have lots of RAM in our osd hosts, so buffering is ok. I`ll trak this issue down further after the weekend! best regards, Ingo ----- Ursprüngliche Mail ----- Von: "Stefan Kooman" <stefan@xxxxxx> An: "ceph-users" <ceph-users@xxxxxxx> Gesendet: Freitag, 7. August 2020 12:24:08 Betreff: Re: OSDs flapping since upgrade to 14.2.10 On 2020-08-07 12:07, Ingo Reimann wrote: > i`m am not sure, if we really have a problem, but it does not look healthy. It might be related to the change that is mentioned in another thread: "block.db/block.wal device performance dropped after upgrade to 14.2.10" TL;DR: bluefs_buffered_io has been changed to "false" in 14.2.10. It doesn't use buffer cache in that case, and in certain workloads (i.e. snap trimming) this seem to have a big impact, even for environments that have large osd_memory_target. I would change that back to "true" ("ceph config set osd bluefs_buffered_io true" should do the trick). Not sure if the OSDs need a restart afterwards, as the config change seem to be effectve immediately for running daemons. Gr. Stefan -- | BIT BV https://www.bit.nl/ Kamer van Koophandel 09090351 | GPG: 0xD14839C6 +31 318 648 688 / info@xxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx -- Ingo Reimann Teamleiter Technik [ https://www.dunkel.de/ ] Dunkel GmbH Philipp-Reis-Straße 2 65795 Hattersheim Fon: +49 6190 889-100 Fax: +49 6190 889-399 eMail: support@xxxxxxxxx https://www.Dunkel.de/ Amtsgericht Frankfurt/Main HRB: 37971 Geschäftsführer: Axel Dunkel Ust-ID: DE 811622001 _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx