In my last blog post I described how to install the VMware Plugin for Docker. Now we will deploy an environment and show how we can use a persistent storage volume across containers.
Build a new volume for a container
docker volume create –driver-vmdk –name BusyBox1 -o size=2gb
You can check the volume with docker volume ls or docker volume inspect commands.
Create a container with persistent storage
docker run –rm -it -v Volumename:/mnt/mymount containerimage.
docker run –rm -it -v BusyBox1:/mnt/myvol busybox
Create a file in the persistent storage
In your container go to the directory you specified in the previous command. In our case it is /mnt/myvol
Create a quick file ex: touch file1 and then add some information to it.
We have created a file in the persistent storage not in the container file system.
Now you can exit your container. ex: exit
Create a different container and attach the persistent volume
I will download a new image for an Ubuntu:latest container and mount the persistent storage volume.
docker run –rm -it -v BusyBox1:/mnt/myvol ubuntu
Change to the same directory /mnt/myvol and see that you can browse the file was created before.
Why is this important?
This allows the developers or administrators to provide a persistent storage that can be used across container reboots to save data outside the container. This can be a great use case for database or shared data that can be used for different containers.
Drop me a comment if you like this type of post.