Hi Dominic, This cluster is running 14.2.8 (nautilus) There's 172 osds divided over 19 nodes. There are currently 10 pools. All pools have 3 replica's of data There are 3968 PG's (the cluster is not yet fully in use. The number of PGs is expected to grow) Marcel > Marcel; > > Short answer; yes, it might be expected behavior. > > PG placement is highly dependent on the cluster layout, and CRUSH rules. > So... Some clarifying questions. > > What version of Ceph are you running? > How many nodes do you have? > How many pools do you have, and what are their failure domains? > > Thank you, > > Dominic L. Hilsbos, MBA > Director - Information Technology > Perform Air International, Inc. > DHilsbos@xxxxxxxxxxxxxx > www.PerformAir.com > > > -----Original Message----- > From: Marcel Kuiper [mailto:ceph@xxxxxxxx] > Sent: Tuesday, July 21, 2020 6:52 AM > To: ceph-users@xxxxxxx > Subject: osd out vs crush reweight > > Hi list, > > I ran a test with marking an osd out versus setting its crush weight to 0. > I compared to what osds pages were send. The crush map has 3 rooms. This > is what happened. > > On ceph osd out 111 (first room; this node has osds 108 - 116) pg's were > send to the following osds > > NR PG's OSD > 2 1 > 1 4 > 1 5 > 1 6 > 1 7 > 2 8 > 1 31 > 1 34 > 1 35 > 1 56 > 2 57 > 1 58 > 1 61 > 1 83 > 1 84 > 1 88 > 1 99 > 1 100 > 2 107 > 1 114 > 2 117 > 1 118 > 1 119 > 1 121 > > All PG's were send to osds on other nodes in the same room, except for 1 > PG on osd 114. I think this works as expected > > Now I marked the osd in and wait until all stabilized. Then I set the > crush weight to 0. ceph osd crush reweight osd.111 0. I thought this > lowers the crush weight of the node so even less chances that PG's end up > on an osd of the same node. However the result are > > NR PG's OSD > 1 61 > 1 83 > 1 86 > 3 108 > 4 109 > 5 110 > 2 112 > 5 113 > 7 114 > 5 115 > 2 116 > > except for 3 PG's all other PG's ended up on an osd belonging to the same > node :-O. Is this expected behaviour? Can someone explain?? This is on > nautilus 14.2.8. > > Thanks > > Marcel > _______________________________________________ > 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 > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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