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Following this guide I have setup cadvisor to monitor the local docker containers. Prometheus is scraping cAdvisor for data which is visualized in Grafana.

I am trying to get disk usage of all the docker containers running on the host. I want to get an output similar to the one shown after running

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 is used to visualize the data. In order to get disk usage I am running the following query to fetch data from Prometheus. 
sum(container_fs_usage_bytes)
Grafana screenshot
The problem is that the value I am getting is the entire value of the overlay filesystem (82GB).
The following rows regarding filesystem usage are shown in cAdvisor (127.0.0.1/metrics)
  # 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
Here is the output of df -h on the host
overlay         228G   39G  178G  18% /var/lib/docker/overlay2/d3de4ea22cdec9aac513d0799b43b0c7fefdb7b75391b6c7b4bc35f46eec817c/merged
How can I get the same values in Grafana from cAdvisor as the ones returned by docker system df  ?
Grafana doesn't collect and store any data. It just visualizes data, which are already collected/stored in some supported time series database.
If cAdvisor is able to get required metrics, then configure cAdvisor storage plugin (InfluxDB is a good start) and visualize them in the Grafana  
                Prometheus is used to store the data. Grafana is used to pull the data from Prometheus. The problem is that the values sent from cAdvisor to Prometheus do not match the ones from  docker system df
– user6386
                Oct 15, 2018 at 8:28
                Then please edit the question and create a Minimal, Complete, and Verifiable example stackoverflow.com/help/mcve
– Jan Garaj
                Oct 15, 2018 at 8:30
        
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