Understanding nfs-provisioner

I’m trying to understand nfs-provisioner as to how it works with persistent storages.
Related to

What I mainly want to know:

If I use a hostPath is there a risk of automatic deletion of its contents?
What is the best method to make absolutely sure that the volume free for provisioning is under no way deleted?

I need to use nfs-provisioner to store some certificates and I need to make sure that they are never gone, whatever happens to the deployment/cluster/whatever.