How to analyze disk usage of a Docker container
I can see that Docker takes 12GB of my filesystem:
2.7G /var/lib/docker/vfs/dir
2.7G /var/lib/docker/vfs
2.8G /var/lib/docker/devicemapper/mnt
6.3G /var/lib/docker/devicemapper/devicemapper
9.1G /var/lib/docker/devicemapper
12G /var/lib/docker
But, how do I know how this is distributed over the containers?
I tried to attach to the containers by running (the new v1.3 command)
docker exec -it <container_name> bash
and then running 'df -h' to analyze the disk usage. It seems to be working, but not with containers that use 'volumes-from'.
For example, I use a data-only container for MongoDB, called 'mongo-data'.
When I run docker run -it --volumes-from mongo-data busybox
, and then df -h
inside the container, It says that the filesystem mounted on /data/db
(my 'mongo-data' data-only container) uses 11.3G, but when I do du -h /data/db
, it says that it uses only 2.1G.
So, how do I analyze a container/volume disk usage? Or, in my case, how do I find out the 'mongo-data' container size?
To see the file size of your containers, you can use the --size
argument of docker ps
:
docker ps --size
After 1.13.0, Docker includes a new command docker system df
to show docker disk usage.
$ docker system df
TYPE TOTAL ACTIVE SIZE RECLAIMABLE
Images 5 1 2.777 GB 2.647 GB (95%)
Containers 1 1 0 B 0B
Local Volumes 4 1 3.207 GB 2.261 (70%)
To show more detailed information on space usage:
$ docker system df --verbose
Posting this as an answer because my comments above got hidden:
List the size of a container:
du -d 2 -h /var/lib/docker/devicemapper | grep `docker inspect -f "{{.Id}}" <container_name>`
List the sizes of a container's volumes:
docker inspect -f "{{.Volumes}}" <container_name> | sed 's/map\[//' | sed 's/]//' | tr ' ' '\n' | sed 's/.*://' | xargs sudo du -d 1 -h
Edit: List all running containers' sizes and volumes:
for d in `docker ps -q`; do
d_name=`docker inspect -f {{.Name}} $d`
echo "========================================================="
echo "$d_name ($d) container size:"
sudo du -d 2 -h /var/lib/docker/devicemapper | grep `docker inspect -f "{{.Id}}" $d`
echo "$d_name ($d) volumes:"
docker inspect -f "{{.Volumes}}" $d | sed 's/map\[//' | sed 's/]//' | tr ' ' '\n' | sed 's/.*://' | xargs sudo du -d 1 -h
done
NOTE: Change 'devicemapper' according to your Docker filesystem (e.g 'aufs')
The volume part did not work anymore so if anyone is insterested I just change the above script a little bit:
for d in `docker ps | awk '{print $1}' | tail -n +2`; do
d_name=`docker inspect -f {{.Name}} $d`
echo "========================================================="
echo "$d_name ($d) container size:"
sudo du -d 2 -h /var/lib/docker/aufs | grep `docker inspect -f "{{.Id}}" $d`
echo "$d_name ($d) volumes:"
for mount in `docker inspect -f "{{range .Mounts}} {{.Source}}:{{.Destination}}
{{end}}" $d`; do
size=`echo $mount | cut -d':' -f1 | sudo xargs du -d 0 -h`
mnt=`echo $mount | cut -d':' -f2`
echo "$size mounted on $mnt"
done
done