Ceph » rgw

start the radosgw without any multisite configuration (default zonegroup and zone will be created)
create a realm , set it as default.
update zonegroup default and zone default using set commands
(this will cause the realm id to change)
update and commit the period

create a new master zonegroup zg0 and a new zg0zo that will the master of zg0
try to update the period, you will get an error as both zonegroups are master.
remove zone default from default zonegroup and delete it.
try period update
the same error and zonegroup default is part of the staging period

workround:
delete .rgw.root: rados purge .rgw.root --yes-i-really-really-mean-it
create a new configuration when the gateway is down:
create a new realm and set it as default
radosgw-admin zonegroup set < json (with the new realm id)
radosgw-admin zoneg set < json (with the new realm id)
set zonegroup and zone as default
period update --commit

reproducible on current master