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.kraftmayer@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 <torkil@drcmr.dk
:
On 07-05-2025 18:16, Anthony D'Atri wrote:
On May 7, 2025, at 5:06 AM, Janne Johansson <icepic.dz@gmail.com>
wrote:
Den ons 7 maj 2025 kl 10:59 skrev Torkil Svensgaard <torkil@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-leave@ceph.io
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-- 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: torkil@drcmr.dk _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io