The operator currently, when deploying Quay, uses the default storage class defined on the cluster for creating backing PVs/PVCs. This in turn creates issues when the default storage class is not suited for db operations. For instance, storage classes based on NFS are extremely bad for databases due to inherent bad design of NFS when it comes to data that dynamically changes.

Setting the storage class manually instead of relying on what is cluster wide will provide more flexibility to the user that deploys Quay.