title: How to rename docker image name?
body: <p>I saved a file whose format is <code>.tar</code> by <code>docker save</code> ,and then I load it into another server by <code>docker load</code>. When it succeeded, the docker give me a tip which is showed in following word.</p>
  
  <pre><code>The image file:V2.0.0Beta1-test already exists, renaming the old one with ID sha256:46952aea8dd30da5a2645d28930381c0ed5f72acd4fac43ea8556cc360d22cf7 to empty string
  Loaded image: file:V2.0.0Beta1-test
  </code></pre>
  
  <p>And the old image should be saved,the new one need to save.What should I do now?</p>