Dear all I have just changed the crush rule for all the replicated pools in the following way: ceph osd crush rule create-replicated replicated_hdd default host hdd ceph osd pool set <poolname> crush_rule replicated_hdd See also this [*] thread Before applying this change, these pools were all using the replicated_ruleset rule where the class is not specified. I am noticing now a problem with the autoscaler: "ceph osd pool autoscale-status" doesn't report any output and the mgr log complains about overlapping roots: [pg_autoscaler ERROR root] pool xyz has overlapping roots: {-18, -1} Indeed: # ceph osd crush tree --show-shadow ID CLASS WEIGHT TYPE NAME -18 hdd 1329.26501 root default~hdd -17 hdd 329.14154 rack Rack11-PianoAlto~hdd -15 hdd 54.56085 host ceph-osd-04~hdd 30 hdd 5.45609 osd.30 31 hdd 5.45609 osd.31 ... ... -1 1329.26501 root default -7 329.14154 rack Rack11-PianoAlto -8 54.56085 host ceph-osd-04 30 hdd 5.45609 osd.30 31 hdd 5.45609 osd.31 ... I have already read about this behavior but I have no clear ideas how to fix the problem. I read somewhere that the problem happens when there are rules that force some pools to only use one class and there are also pools which does not make any distinction between device classes All the replicated pools are using the replicated_hdd pool but I also have some EC pools which are using a profile where the class is not specified. As far I understand, I can't force these pools to use only the hdd class: according to the doc I can't change this profile specifying the hdd class (or at least the change wouldn't be applied to the existing EC pools) Any suggestions ? The crush map is available at https://cernbox.cern.ch/s/gIyjbQbmoTFHCrr, if you want to have a look Many thanks, Massimo [*] https://www.mail-archive.com/ceph-users@ceph.io/msg18534.html