Questions regarding persistent storage management and registry

Issue

• The internal registry on our OSE 3.1 environment ran out of persistent storage. We already pruned old images using oadm prune.

1. How can I upgrade to a larger persistent volume without losing existing data? I didn't find anything about this in the documentation.

2. How can I list all images in the internal registry? It doesn't seem to support the Docker Registry V2 Catalog API. I suspect some old images from previous OSE 3 versions don't get pruned correctly.

OSE 3.1, internal docker registry with attached NFSv4 persistent volume. Environment was upgraded multiple times from earlier OSE 3 versions.
This is a test environment. However we will install a production environment shortly and the issues will apply there too.