In the client we use the term "RootFS` when referring to snapshots. This is confusing terminology, we should refer to a rootfs as either a set of mounts to create a rootfs or a directory which can be used as a rootfs. In the client we should use the term snapshots to refer to any identifier which is to be used with a snapshotter.

Naming might look like...

• WithSnapshot - would take in existing snapshot
• WithNewSnapshot - formerly WithNewRootFS (could also be called WithNewActiveSnapshot?)
• WithNewSnapshotView - formerly WithNewReadonlyRootFS
• WithRootFS - would take in mounts and use them directly
• WithRootFSPath - would take in local directory to bind mount as rootfs