Hi Torkil, I would be interested in your results. It's been a few years since I saw the LRC plugin in production. Does anyone else in the ceph community use it? Joachim
joachim.kraftma...@clyso.com www.clyso.com Hohenzollernstr. 27, 80801 Munich Utting | HR: Augsburg | HRB: 25866 | USt. ID-Nr.: DE275430677 Am Mi., 7. Mai 2025 um 21:00 Uhr schrieb Torkil Svensgaard <tor...@drcmr.dk >: > > > On 07-05-2025 18:16, Anthony D'Atri wrote: > > > > > >> On May 7, 2025, at 5:06 AM, Janne Johansson <icepic...@gmail.com> > wrote: > >> > >> Den ons 7 maj 2025 kl 10:59 skrev Torkil Svensgaard <tor...@drcmr.dk>: > >>> We are looking at a cluster split between two DCs with the DCs as > >>> failure domains. > >>> > >>> Am I right in assuming that any recovery or backfill taking place > should > >>> largely happen inside each DC and not between them? Or can no such > >>> assumptions be made? > >>> Pools would be EC 4+8, if that matters. > >> > >> Unless I am mistaken, the first/primary of each PG is the one "doing" > >> the backfills, so if the primaries are evenly distributed between the > >> sites, the source of all backfills would be in the remote DC in 50% of > >> the cases. > > > > Are we talking about recovery, or backfill? > > I was asking about both > > >> I do not think the backfills are going to calculate how it can use > >> only "local" pieces to rebuild a missing/degraded PG piece without > >> going over the DC-DC link even if it is theoretically possible. > > > > The LRC plugin might be able to localize *recovery*, but backfill from > adding OSDs, changing CRUSH rules, etc. would always have to hit both. > > Thanks both, I'll take a look at the LRC plugin. > > Mvh. > > Torkil > > >> -- > >> May the most significant bit of your life be positive. > >> _______________________________________________ > >> ceph-users mailing list -- ceph-users@ceph.io > >> To unsubscribe send an email to ceph-users-le...@ceph.io > > _______________________________________________ > > ceph-users mailing list -- ceph-users@ceph.io > > To unsubscribe send an email to ceph-users-le...@ceph.io > > -- > Torkil Svensgaard > Sysadmin > MR-Forskningssektionen, afs. 714 > DRCMR, Danish Research Centre for Magnetic Resonance > Hvidovre Hospital > Kettegård Allé 30 > DK-2650 Hvidovre > Denmark > Tel: +45 386 22828 > E-mail: tor...@drcmr.dk > _______________________________________________ > ceph-users mailing list -- ceph-users@ceph.io > To unsubscribe send an email to ceph-users-le...@ceph.io > _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
