Elastic stack 7.9.2 - my /var/lib/docker is heavy

Hi Everyone,

I've noticed that my folder /var/lib/docker is pretty huge for all ELK nodes. It's from 2GB up to 6GB (depending on how many dockers is running on a virtual server). When I stop running dockers (let's say on a first elk node) the size of /var/lib/docker is getting lower: from 2.6 GB to 1.3 GB. I"ve removed all unused dockers images and volumes - no changes. I have persistent volumes mounted in a docker-compose file:

      - /srv/data:/usr/share/elasticsearch/data
      - /srv/Docker/config:/usr/share/elasticsearch/config
      - /srv/Docker/logs:/usr/share/elasticsearch/logs
      - /srv/backup:/usr/share/elasticsearch/backup
      - /srv/backup2:/usr/share/elasticsearch/backup2

Dockers should be stateless - what's wrong with my config ?