is ceph balancer doing anything?
Hello everyone, A few weeks ago I have enabled the ceph balancer on my cluster as per the instructions here: [ https://docs.ceph.com/docs/mimic/mgr/balancer/ | https://docs.ceph.com/docs/mimic/mgr/balancer/ ] I am running ceph version: ceph version 13.2.6 (7b695f835b03642f85998b2ae7b6dd093d9fbce4) mimic (stable) The cluster has 48 osds (40 osds in hdd pools and 8 osds in ssd pool) Currently, the balancer status is showing as Active. # ceph balancer status { "active": true, "plans": [], "mode": "upmap" } The health status of the cluster is: health: HEALTH_OK Previously, I've used the old REWEIGHT to change the placement of data as I've seen very uneven usage (ranging from about 60% usage on some OSDs to over 90% on others). So, I have a number of osds with reweight of 1 an some going down to 0.75. At the moment the osd usage ranges between about 65% to to just under 90%, so still a huge variation. After switching on the balancer, I've not actually seen any activity or data migration, so I am not sure if the balancer is working at all. Could someone tell me how do I check if balancing is doing its job? The second question is as the balancer is now switched on, do I suppose to set the reweight values back to their default value of 1? Many thanks
Hello Andrei, I have kinda the same problem but because it's production and i don't want to do sudden moves that will have data redistribution and affect clients ( only with change approval and stuff) but from what i played into other test clusters and according to documentation... you need to also set the crush compact mode. (you can even configure a plan if you want). After it finishes the balance then i believe you can turn off the balancer (you don't have to have it on all the time)
participants (2)
-
Andrei Mikhailovsky
-
tdados@hotmail.com