kolla-ansible opnestack,cinder.exception.NoValidBackend: No valid backend was found - openstack

Question

kolla-ansible (stable/ussuri) (openstack ussuri)
kolla-ansible deploy openstack(four node with ubuntu18.04)
configuration cinder with an existing ceph(cephadm deployed,ceph version 15.2.8,octopus (stable) );
cinder-volume | server1#ceph | nova | enabled | down |
how to fix this, thanks.
logs
(venv36) root#dev ~/kolla-ansible (stable/ussuri) $ cinder service-list
+------------------+------------------------+------+---------+-------+----------------------------+---------+-----------------+---------------+
| Binary | Host | Zone | Status | State | Updated_at | Cluster | Disabled Reason | Backend State |
+------------------+------------------------+------+---------+-------+----------------------------+---------+-----------------+---------------+
| cinder-backup | server1 | nova | enabled | up | 2021-02-22T07:22:53.000000 | - | - | |
| cinder-backup | server2 | nova | enabled | up | 2021-02-22T07:22:55.000000 | - | - | |
| cinder-backup | server3 | nova | enabled | up | 2021-02-22T07:22:50.000000 | - | - | |
| cinder-backup | server4 | nova | enabled | up | 2021-02-22T07:22:50.000000 | - | - | |
| cinder-scheduler | server1 | nova | enabled | up | 2021-02-22T07:22:49.000000 | - | - | |
| cinder-scheduler | server2 | nova | enabled | up | 2021-02-22T07:22:56.000000 | - | - | |
| cinder-scheduler | server3 | nova | enabled | up | 2021-02-22T07:22:53.000000 | - | - | |
| cinder-volume | server1#ceph | nova | enabled | down | 2021-02-22T01:21:03.000000 | - | - | - |
| cinder-volume | server1#rbd-1#rbd-1 | nova | enabled | down | 2021-02-21T07:41:14.000000 | - | - | - |
| cinder-volume | storage1:volumes#rbd-1 | nova | enabled | down | 2021-02-21T07:07:29.000000 | - | - | - |
+------------------+------------------------+------+---------+-------+----------------------------+---------+-----------------+---------------+
tree /etc/kolla/
/etc/kolla/config/
├── cinder
│   ├── ceph.conf
│   ├── cinder-backup
│   │   ├── ceph.client.cinder-backup.keyring
│   │   └── ceph.client.cinder.keyring
│   ├── cinder-backup.conf
│   ├── cinder-volume
│   │   └── ceph.client.cinder.keyring
│   ├── cinder-volume.conf
│   └── cinder-volume.conf.bak
├── glance
│   ├── ceph.client.glance.keyring
│   ├── ceph.conf
│   └── glance-api.conf
└── nova
├── ceph.client.cinder.keyring
├── ceph.client.nova.keyring
├── ceph.conf
└── nova-compute.conf
cinder_volume,cinder_scheduler logs as following:
2021-02-22 14:08:20.766 7
ERROR cinder.scheduler.flows.create_volume
[req-1e4cc16b-cace-4019-8ce5-9f543e758e77 2ff1ec3c53da405e90a71c993cf969eb c7675e760bbd498f9bc143cd165c4099 -
default default] Failed to run task cinder.scheduler.flows.create_volume.ScheduleCreateVolumeTask;
volume:create: No valid backend was found. No weighed backends available: cinder.exception.NoValidBackend:
No valid backend was found. No weighed backends available
(venv36) root#dev ~/kolla-ansible (stable/ussuri) $ cat /etc/kolla/config/cinder/cinder-volume.conf
[DEFAULT]
enabled_backends=ceph
[ceph]
rbd_ceph_conf=/etc/ceph/ceph.conf
rbd_user=cinder
rbd_pool=volumes
volume_backend_name=ceph
#backend_host=storage1:volumes
backend_host=server1
volume_driver=cinder.volume.drivers.rbd.RBDDriver
rbd_secret_uuid = 67ca7759-ea2b-4bd0-9464-d771382b13c7