Emptying docker registry

[Vamshi Madhavaram]

My EC2 devops server (20GB root volume) is low on available disk space and I noticed blobs in docker registry folder is taking up close to 10GB space. When I pruned docker images I noticed bunch of containers are removed but the 10GB registry folder size remained the same. 

I have about 11 images running (9 for harbor and 2 for jenkins) on this EC2 instance. We use jenkins to trigger a docker build and push all our application specific images to harbor which has another 100GB EBS volume attached to this devops EC2 instance. 

This devops server was not setup by me.Trying to understand the real use of this docker registry and if it can be safely emptied. I need to free up some space on the root folder as Jenkins home folder is out of space. 

Any suggestions please?

Thanks,

Vamshi.