Comment 4 for bug 1821696

So the fact that Nova is even creating an encryptor object in the first place is incorrect. Reviewing our _detach_encryptor code suggests that the volume secrets have gone missing in order for this to happen:

https://github.com/openstack/nova/blob/9bb78d5765dab01e38327f57312583c189a352d5/nova/virt/libvirt/driver.py#L1381-L1382

Did you manually remove the associated libvirt secrets for this volume?

These should persist reboots as they are created with ephemeral=False by default.