[erlang-questions] Streaming a folder from one node to another

[ok@REDACTED]

Re streaming an arbitrarily large folder from one node to another
in a cluster:

1. Why is it necessary to do this?
   Why is it impossible or undesirable to just serve blocks from
   the files to the other node on demand?

2. You seem to be suggesting that it is necessary to communicate
   the whole thing in one go.  Why is it not possible to set up
   a common initial state and stream changes?

3. What are you going to do if the contents of the folder change
   faster than you can stream them?

4. I'm wondering about the cost of streaming vs the cost of simply
   switching the storage device from one node's control to
   another's.  (In the extreme, getting a human to swap cables.
   I mean, that could take just seconds.  Electronic switching would
   likely be better.  And yes, I'm thinking of old "truck of tapes"
   ideas.)  Surely the cluster is equipped to switch devices from
   one CPU board to another in order to handle CPU board failure...