In particular, the following storage features are moving to GA in Kubernetes 1.18:
- Raw Block Support: Allow volumes to be surfaced as block devices inside containers instead of just mounted filesystems.
- Volume Cloning: Duplicate a PersistentVolumeClaim and underlying storage volume using the Kubernetes API via CSI.
- CSIDriver Kubernetes API Object: Simplifies CSI driver discovery and allows CSI Drivers to customize Kubernetes behavior.

- CoreDNS is now the default DNS server in kube-up deployments.  ([#69883](https://github.com/kubernetes/kubernetes/pull/69883), [@chrisohaver](https://github.com/chrisohaver))
- Opt out of chowning and chmoding from kubectl cp. ([#69573](https://github.com/kubernetes/kubernetes/pull/69573), [@bjhaid](https://github.com/bjhaid))

feature parity with in-tree functionality, including functionality like resizing, inline volumes, and more. SIG Storage introduces new alpha functionality in CSI that doesn't exist in the Kubernetes Storage subsystem yet, like volume cloning.

Volume cloning enables users to specify another PVC as a "DataSource" when provisioning a new volume. If the underlying storage system supports this functionality and implements the "CLONE_VOLUME" capability in its CSI driver, then the new volume...

- Add CSI Migration Shim for VerifyVolumesAreAttached and BulkVolumeVerify ([#80443](https://github.com/kubernetes/kubernetes/pull/80443), [@davidz627](https://github.com/davidz627))
- Promotes VolumePVCDataSource (Cloning) feature to beta for 1.16 release ([#81792](https://github.com/kubernetes/kubernetes/pull/81792), [@j-griffith](https://github.com/j-griffith))