I've used oc cp to copy files and directories onto a persistent volume attached to a pod in my openshift project. Is there any way to delete?
You can use oc exec to execute any command inside the container, so you can use the following to execute rm within the container to delete files:
oc exec <pod-name> rm /path/to/my-file
or to recursively delete a folder within the container:
oc exec <pod-name> rm -rf /path/to/my/directory
Alternatively, you can use oc rsh <pod-name> to open an interactive terminal if the Pod contains a shell binary.