簡介：
Harbor私有倉庫運行一段時間后，倉庫中存有大量鏡像，會占用太多的存儲空間。直接通過Harbor界面刪除相關鏡像，並不會自動刪除存儲中的文件和鏡像。需要停止Harbor服務，執行垃圾回收命令，進行存儲空間清理和回收。
相關資料：
1、Harbor用戶手冊中的相關說明：
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:
#要啟用垃圾回收（GC），首先要關閉Harbor服務，然后再執行清理命令
#停止Harbor相關服務
$ docker-compose stop
#使用--dry-run參數運行容器，預覽運行效果，但不刪除任何數據
$ 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參數，將刪除相關的文件和鏡像，
$ docker run -it --name gc --rm --volumes-from registry vmware/registry:2.6.2-photon garbage-collect /etc/registry/config.yml
#重新啟動Harbor相關服務
$ docker-compose start
圖1：01-先在Harbor UI圖形界面中刪除不需要的鏡像
圖2：02-停止Harbor服務，執行垃圾回收命令
2、數人雲CTO肖總微信公號的文章：
圖3：老肖說兩句截圖
圖4：數人雲CTO肖總-微信公眾號-老肖說兩句
參考鏈接：
Harbor用戶指南
https://github.com/vmware/harbor/blob/master/docs/user_guide.md
刪除容器鏡像倉庫中的容器鏡像到底有多難？
Garbage collection
https://github.com/docker/docker.github.io/blob/master/registry/garbage-collection.md