简介：
Harbor私有仓库运行一段时间后，仓库中存有大量镜像，会占用太多的存储空间。直接通过Harbor界面删除相关镜像，并不会自动删除存储中的文件和镜像。需要停止Harbor服务，执行垃圾回收命令，进行存储空间清理和回收。
相关资料：
1、Harbor用户手册中的相关说明：
Next, delete the actual files of the repository using the registry's garbage collection(GC). Make sure that no one is pushing images or Harbor is not running at all before you perform a GC. If someone were pushing an image while GC is running, there is a risk that the image's layers will be mistakenly deleted which results in a corrupted image. So before running GC, a preferred approach is to stop Harbor first.
Run the below commands on the host which Harbor is deployed on to preview what files/images will be affected:
#要启用垃圾回收（GC），首先要关闭Harbor服务，然后再执行清理命令
#停止Harbor相关服务
$ docker-compose stop
#使用--dry-run参数运行容器，预览运行效果，但不删除任何数据
$ docker run -it --name gc --rm --volumes-from registry vmware/registry:2.6.2-photon garbage-collect --dry-run /etc/registry/config.yml
#NOTE: The above option "--dry-run" will print the progress without removing any data.
Verify the result of the above test, then use the below commands to perform garbage collection and restart Harbor.
#不使用--dry-run参数，将删除相关的文件和镜像，
$ docker run -it --name gc --rm --volumes-from registry vmware/registry:2.6.2-photon garbage-collect /etc/registry/config.yml
#重新启动Harbor相关服务
$ docker-compose start
图1：01-先在Harbor UI图形界面中删除不需要的镜像
图2：02-停止Harbor服务，执行垃圾回收命令
2、数人云CTO肖总微信公号的文章：
图3：老肖说两句截图
图4：数人云CTO肖总-微信公众号-老肖说两句
参考链接：
Harbor用户指南
https://github.com/vmware/harbor/blob/master/docs/user_guide.md
删除容器镜像仓库中的容器镜像到底有多难？
http://mp.weixin.qq.com/s?__biz=MzA4ODgwNTk1NQ==&mid=2649949694&idx=1&sn=eda4513942458714a1eb89aaa25c9954&chksm=882322d2bf54abc4cb4e5c37fe348e2849c14f3d7e2897a0d839a045d8789640a1b99ca26d44&mpshare=1&scene=2&srcid=0226hpbvbowRZphA0jkqkTlq&from=timeline#rd
Garbage collection
https://github.com/docker/docker.github.io/blob/master/registry/garbage-collection.md