How to increase Docker container default size?

Question

We have created docker image with default size of 10GB and we have loaded cassandra data now it is full means there is no space. Can anyone tell how to increase the docker container size to 40GB from 10GB without loss of existing data.

Answer 1

I don't think it is possible (without the losing of the data). Here is how you enlarge the basesize:

1. (optional) If you have already downloaded any image via docker pull you need to clean them first - otherwise they won't be resized

   docker rmi your_image_name

2. Edit the storage config

   vi /etc/sysconfig/docker-storage

   There should be something like DOCKER_STORAGE_OPTIONS="...", change it to DOCKER_STORAGE_OPTIONS="... --storage-opt dm.basesize=100G"

3. Restart the docker deamon

   service docker restart

4. Pull the image

   docker pull your_image_name

5. (optional) verification

   docker run -i -t your_image_name /bin/bash

   df -h

I was struggling with this a lot until I found out this link http://www.projectatomic.io/blog/2016/03/daemon_option_basedevicesize/ turns out you have to remove/pull image after enlarging the basesize.