title: Number of nodes AWS Elasticsearch
body: <p>I read documentation, but unfortunately I still don't understand one thing. While creating AWS Elasticsearch domain, I need to choose "Number of nodes" in "Data nodes" section.
  If i specify 3 data nodes and 3-AZ, what it actually means?
  <a href="https://i.stack.imgur.com/oilbr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oilbr.png" alt="enter image description here"></a>
  I have suggestions:</p>
  
  <ol>
  <li><p>I'll get 3 nodes with their own storages (EBS). One of node is master and other 2 are replicas in different AZ. Just copy of master,  not to lose data if master node become broken.</p></li>
  <li><p>I'll get 3 nodes with their own storages (EBS). All of them will work independent and on their storadges are different data. So at the same time data can be processed by different nodes and store on different storages.</p></li>
  </ol>
  
  <p>It looks like in other AZ's should be replicas. but then I don't understand why I have different values of free space on different nodes <a href="https://i.stack.imgur.com/lSAp0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lSAp0.png" alt="enter image description here"></a></p>
  
  <p>Please, explain how it works.
  Many thanks for any info or links.</p>