title: Should I use save/load or export/import for my application using Docker? And an additional uncertainty
body: <p>Without hardly any knowledge of Docker, I made a program that remotely manages images and containers for many PCs (robotic platforms) on a local network.  All of the PCs are the same with a lightweight OS that supports docker natively.  The goal is now that an image has been made which has all of the drivers and packages necessary to create 'missions' for the robot, I can use any computer with docker to start a container from that image, program a mission, then save the container and send it to any of the PCs which are robotic platforms.  Then I see myself running the container and just starting the mission.</p>
  
  <p>My question is this: currently my image is 2.4 GB as a base (and will possibly grow).  Should I use <strong>save/load</strong> or <strong>import/export</strong>?  Reading how save holds onto the layers, export sounds better for storage.  </p>
  
  <p>Then my generic docker uncertainty is can I mix/match (save and import) or (export and load)?</p>
  
  <p>Super bonus docker question: I'd like to check a file to see if it's a valid image (saved or exported).  Is there a simple offset I can check for a few bytes that would confirm it is a docker image?  I couldn't find docker header file information online.</p>
  
  <p>Thanks!</p>