CHAPTER 8. PRUNING OBJECTS TO RECLAIM RESOURCES For example, you can still create a Pod referencing an image as pruning identifies that image for pruning. You should still keep track of an API object created during the pruning operations that might reference images so that you can mitigate any references to deleted content. Re-doing the pruning without the  --prune-registry  option or with  --prune-registry=true  does not lead to pruning the associated storage in the image registry for images previously pruned by  --prune- registry=false . Any images that were pruned with  --prune-registry=false  can only be deleted from registry storage by hard pruning the registry. 8.6.2. Running the image prune operation Procedure 8.6.3. Using secure or insecure connections The secure connection is the preferred and recommended approach. It is done over HTTPS protocol with a mandatory certificate verification. The  prune  command always attempts to use it if possible. If it is not possible, in some cases it can fall-back to insecure connection, which is dangerous. In this case, either certificate verification is skipped or plain HTTP protocol is used. The fall-back to insecure connection is allowed in the following cases unless  --certificate-authority  is specified: 1. The  prune  command is run with the  --force-insecure  option. 2. The provided  registry-url  is prefixed with the  http://  scheme. 3. The provided  registry-url  is a local-link address or  localhost . 4. The configuration of the current user allows for an insecure connection. This can be caused by the user either logging in using  --insecure-skip-tls-verify  or choosing the insecure connection when prompted. 117 1. To see what a pruning operation would delete: a. Keeping up to three tag revisions, and keeping resources (images, image streams, and pods) younger than 60 minutes: b. Pruning every image that exceeds defined limits: 2. To perform the prune operation with the options from the previous step: $ oc adm prune images --keep-tag-revisions=3 --keep-younger-than=60m $ oc adm prune images --prune-over-size-limit $ oc adm prune images --keep-tag-revisions=3 --keep-younger-than=60m --confirm $ oc adm prune images --prune-over-size-limit --confirm