Let's say you have a Persistent Volume named my-persistent-volume. The oc describe persistentvolume command can be used to list the labels currently associated with the Persistent Volume.

~]$ oc describe persistentvolume my-persistent-volume
Name:            my-persistent-volume
Labels:          <none>

The oc label persistentvolume command can be used to apply one or more labels to the Persistent Volume.

oc label persistentvolume my-persistent-volume region=east

You can then use the oc describe persistentvolume command again to see that the Persistent Volume has the label.

~]$ oc describe persistentvolume my-persistent-volume
Name:            my-persistent-volume
Labels:          region=east

And here is how you would remove a label from a Persistent Volume.

oc label persistentvolume my-persistent-volume region-