We're going to be using Longhorn for persistent storage. Longhorn
allocates space on worker nodes and exposes iSCSI LUNs to other worker
nodes. It creates sparse filesystem images under `/var/lib/longhorn`
for each volume. Thus, we need to mount a large filesystem at that
path on each worker node for Longhorn to use.
Using two different kickstart scripts, one for the control plane nodes,
and one for the worker nodes, we can properly mount the Longhorn data
directory only on machines that will be running the Longhorn manager.
Longhorn only supports *ext4* and *XFS* filesystem types.
Dustin