ceph osd set-group

If you don’t want to set flags for the whole cluster, like noout or noup. Then you can also use ceph osd set-group and ceph osd unset-group to set the appropriate flag for a group of osds or even whole hosts.

ceph osd set-group <flags> <who>
ceph osd unset-group <flags> <who>

for example set noout for a whole host with osds

ceph osd set-group noout clyso-ceph-node3
root@clyso-ceph-node1:~# ceph health detail
HEALTH_WARN 1 OSDs or CRUSH {nodes, device-classes} have {NOUP,NODOWN,NOIN,NOOUT} flags set
[WRN] OSD_FLAGS: 1 OSDs or CRUSH {nodes, device-classes} have {NOUP,NODOWN,NOIN,NOOUT} flags set
    host clyso-ceph-node3 has flags noout
ceph osd unset-group noout clyso-ceph-node3
root@clyso-ceph-node1:~# ceph health detail
HEALTH_OK
root@clyso-ceph-node1:

Sources:

https://docs.ceph.com/en/quincy/rados/operations/health-checks/#osd-flags