You asked about exactly this before: https://lists.ceph.io/hyperkitty/list/ceph-users@xxxxxxx/thread/IGYCYJTAMBDDOD2AQUCJQ6VSUWIO4ELW/#ZJU3555Z5WQTJDPCTMPZ6LOFTIUKKQUS It is not possible to avoid remapping, because if the PGs are not remapped you would have degraded redundancy. In any storage system, this degradation is exactly what needs to be avoided/fixed at all cost. I don't see an issue with health status messages issued by self-healing. That's the whole point of ceph, just let it do its job and don't get freaked out by health_warn. You can, however try to keep the window of rebalancing short and this is exactly what was discussed in the thread above already. As is pointed out there as well, even this is close to pointless. Just deploy a few more disks than you need, let the broken ones go and be happy that ceph is taking care of the rest and even tells you about its progress. Best regards, ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Tony Liu <tonyliu0592@xxxxxxxxxxx> Sent: 03 February 2021 03:10:26 To: ceph-users@xxxxxxx Subject: replace OSD without PG remapping Hi, There are multiple different procedures to replace an OSD. What I want is to replace an OSD without PG remapping. #1 I tried "orch osd rm --replace", which sets OSD reweight 0 and status "destroyed". "orch osd rm status" shows "draining". All PGs on this OSD are remapped. Checked "pg dump", can't find this OSD any more. 1) Given [1], setting weight 0 seems better than setting reweight 0. Is that right? If yes, should we change the behavior of "orch osd rm --replace"? 2) "ceph status" doesn't show anything about OSD draining. Is there any way to see the progress of draining? Is there actually copy happening? The PG on this OSD is remapped and copied to another OSD, right? 3) When OSD is replaced, there will be remapping and backfilling. 4) There is remapping in #2 and remapping again in #3. I want to avoid it. #2 Is there any procedure that doesn't mark OSD out (set reweight 0), neither set weight 0, which should keep PG map unchanged, but just warn about less redundancy (one out of 3 OSDs of PG is down), and when OSD is replaced, no remapping, just data backfilling? [1] https://ceph.com/geen-categorie/difference-between-ceph-osd-reweight-and-ceph-osd-crush-reweight/ Thanks! Tony _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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