cAdvisor显示的磁盘使用情况

在this指南后，我设置了cadvisor来监控本地docker容器 . Prometheus正在 grab cAdvisor获取Grafana中可视化的数据 .

我试图获取在主机上运行的所有docker容器的磁盘使用情况 . 我希望获得类似于运行后显示的输出

docker system df
TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              21                  10                  1.18GB              489.9MB (41%)
Containers          10                  8                   27B                 0B (0%)
Local Volumes       16                  5                   2.369GB             1.615GB (68%)
Build Cache         0                   0                   0B                  0B

Grafana用于可视化数据 . 为了获得磁盘使用率，我运行以下查询以从Prometheus获取数据 .

sum(container_fs_usage_bytes)

Grafana screenshot

问题是我得到的值是覆盖文件系统的整个值（82GB） .

关于文件系统使用的以下行显示在cAdvisor（127.0.0.1/metrics）中

# TYPE container_fs_usage_bytes gauge
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="",container_label_com_docker_compose_container_number="",container_label_com_docker_compose_oneoff="",container_label_com_docker_compose_project="",container_label_com_docker_compose_service="",container_label_com_docker_compose_version="",container_label_maintainer="",container_label_org_label_schema_group="",device="/dev/sda2",id="/",image="",name=""} 4.4317888512e+10
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="",container_label_com_docker_compose_container_number="",container_label_com_docker_compose_oneoff="",container_label_com_docker_compose_project="",container_label_com_docker_compose_service="",container_label_com_docker_compose_version="",container_label_maintainer="",container_label_org_label_schema_group="",device="overlay",id="/",image="",name=""} 4.4317888512e+10
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="",container_label_com_docker_compose_container_number="",container_label_com_docker_compose_oneoff="",container_label_com_docker_compose_project="",container_label_com_docker_compose_service="",container_label_com_docker_compose_version="",container_label_maintainer="",container_label_org_label_schema_group="",device="shm",id="/",image="",name=""} 0
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="",container_label_com_docker_compose_container_number="",container_label_com_docker_compose_oneoff="",container_label_com_docker_compose_project="",container_label_com_docker_compose_service="",container_label_com_docker_compose_version="",container_label_maintainer="",container_label_org_label_schema_group="",device="tmpfs",id="/",image="",name=""} 0
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="0616b7e25768c2764fd083b53a061c53c6a2ffea9f8d5e74f6ec61fbc03aeeba",container_label_com_docker_compose_container_number="1",container_label_com_docker_compose_oneoff="False",container_label_com_docker_compose_project="dockprom",container_label_com_docker_compose_service="prometheus",container_label_com_docker_compose_version="1.17.1",container_label_maintainer="The Prometheus Authors <prometheus-developers@googlegroups.com>",container_label_org_label_schema_group="monitoring",device="/dev/sda2",id="/docker/6fbef095b2cf0c3f65e906d4ddca4102cd0646590c4003e50186af40f02ef805",image="prom/prometheus:v2.4.2",name="prometheus"} 409600
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="19747419ff433903067d8681ee6149861347fcf65e7db246f4b56301feb53b78",container_label_com_docker_compose_container_number="1",container_label_com_docker_compose_oneoff="False",container_label_com_docker_compose_project="dockprom",container_label_com_docker_compose_service="caddy",container_label_com_docker_compose_version="1.17.1",container_label_maintainer="",container_label_org_label_schema_group="monitoring",device="/dev/sda2",id="/docker/611fe3e5812d9c3a3abc9dab27fd8a91f68c2e3acc3257b5926eae0cbf8914cf",image="stefanprodan/caddy",name="caddy"} 53248
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="38ec70818559317528d83c7c8d889ab9ff2dcd78637a3e9cae71083014abc281",container_label_com_docker_compose_container_number="1",container_label_com_docker_compose_oneoff="False",container_label_com_docker_compose_project="dockprom",container_label_com_docker_compose_service="grafana",container_label_com_docker_compose_version="1.17.1",container_label_maintainer="",container_label_org_label_schema_group="monitoring",device="/dev/sda2",id="/docker/70cdb5ec332973c7a70cf339f5abc48afa5d8f6e6ff5ba0216031ff1c86aa2c5",image="grafana/grafana:5.2.4",name="grafana"} 204800
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="42eb1e0967f80c097581f64bace779010aac94368f2fd366215b2a2506340a60",container_label_com_docker_compose_container_number="1",container_label_com_docker_compose_oneoff="False",container_label_com_docker_compose_project="dockprom",container_label_com_docker_compose_service="pushgateway",container_label_com_docker_compose_version="1.17.1",container_label_maintainer="The Prometheus Authors <prometheus-developers@googlegroups.com>",container_label_org_label_schema_group="monitoring",device="/dev/sda2",id="/docker/39049775176f8315f4ee3acf8167a6986ee1ce4fe89cebc20061accec8cdb5cf",image="prom/pushgateway",name="pushgateway"} 69632
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="58ee943e7e48ae304fa7040d44ebeeb440627d311716a70665f4c43f16e6ad54",container_label_com_docker_compose_container_number="1",container_label_com_docker_compose_oneoff="False",container_label_com_docker_compose_project="dockprom",container_label_com_docker_compose_service="nodeexporter",container_label_com_docker_compose_version="1.17.1",container_label_maintainer="",container_label_org_label_schema_group="monitoring",device="/dev/sda2",id="/docker/6f4c169111b89ea2bb857fbd0cf52c1c729b17dbdd8e7a8e011a1f9ba7128e90",image="prom/node-exporter:v0.16.0",name="nodeexporter"} 184320
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="db9a938539bf7f1b610cda7420e62088d2bd27c50f52b2510b3bfc9d6c099744",container_label_com_docker_compose_container_number="1",container_label_com_docker_compose_oneoff="False",container_label_com_docker_compose_project="dockprom",container_label_com_docker_compose_service="cadvisor",container_label_com_docker_compose_version="1.17.1",container_label_maintainer="",container_label_org_label_schema_group="monitoring",device="/dev/sda2",id="/docker/2d9fee9bd94d9d627259f04e17468840700a78267a894f3fbedda0d375c5e985",image="google/cadvisor:v0.31.0",name="cadvisor"} 86016
  container_fs_usage_bytes{container_label_com_docker_compose_config_hash="fdcc8c8d658803bc1254fab7a308bc999f76e777a0f414d2f6c58024530cdfa8",container_label_com_docker_compose_container_number="1",container_label_com_docker_compose_oneoff="False",container_label_com_docker_compose_project="dockprom",container_label_com_docker_compose_service="alertmanager",container_label_com_docker_compose_version="1.17.1",container_label_maintainer="",container_label_org_label_schema_group="monitoring",device="/dev/sda2",id="/docker/c6f72c08c11cfd862fa565bfd190744555ff2d345dfce553b8839a4d13c0d0d2",image="prom/alertmanager:v0.15.2",name="alertmanager"} 73728

这是主机上 df -h 的输出

overlay         228G   39G  178G  18% /var/lib/docker/overlay2/d3de4ea22cdec9aac513d0799b43b0c7fefdb7b75391b6c7b4bc35f46eec817c/merged

如何从cAdvisor获取Grafana中与 docker system df 返回的值相同的值？