I install ceilometer and gnocchi and every thing work fine and I use https://docs.openstack.org/ceilometer... and it gather whole volume size ,snapshot size, backup size
but I can not get volume usage forexample if I have 1TB volume and the vm use 100GB it should show 100GB not 1TB. how can I see volume usage this is my polling.yaml

---
sources:
    - name: some_pollsters
      interval: 60
      meters:
        - cpu
        - cpu_l3_cache
        - memory.usage
        - network.incoming.bytes
        - network.incoming.packets
        - network.outgoing.bytes
        - network.outgoing.packets
        - disk.device.read.bytes
        - disk.device.read.requests
        - disk.device.write.bytes
        - disk.device.write.requests
        - hardware.cpu.util
        - hardware.memory.used
        - hardware.memory.total
        - hardware.memory.buffer
        - hardware.memory.cached
        - hardware.memory.swap.avail
        - hardware.memory.swap.total
        - hardware.system_stats.io.outgoing.blocks
        - hardware.system_stats.io.incoming.blocks
        - hardware.network.ip.incoming.datagrams
        - hardware.network.ip.outgoing.datagrams
        - disk.device.usage
        - volume.size
        - snapshot.size
        - volume.provider.capacity.total
        - volume.provider.capacity.free
        - volume.provider.capacity.allocated
        - volume.provider.capacity.provisioned
        - volume.provider.capacity.virtual_free
        - volume.provider.pool.capacity.total
        - volume.provider.pool.capacity.free
        - volume.provider.pool.capacity.allocated
        - volume.provider.pool.capacity.provisioned
        - volume.provider.pool.capacity.virtual_free