Proposed title of this feature request :

Enable use of `use_hard_links` in storage configuration file

Describe your problem. Include specific actions and error messages. :

We are deploying SNO openshift on some very small environments where we need to preserve as much disk space as possible. For our basic setup, we have tested out the `use_hard_links` setting in the storage configuration which has saved 30-40GB of memory across our hosts. We would like to have a supported configuration which allows us to set this to true without overriding the entire file. The setting is currently hardcoded here:

https://github.com/openshift/machine-config-operator/blob/679b9b5206db33ae9ae3816bdc3f8db61c5d2488/templates/common/_base/files/container-storage.yaml#L63