title: Amazon EC2 with or without EBS?
body: <p>Still reading up on AWS.
  Amazon Large Instances comes with 850GB local storage. 
  However, i read in case of failover and we want to power up another instance, we can just mount a EBS volume on it and start running right?  That will mean that we have to configure and store it on a EBS volume to enjoy this capability. 
  Does that mean that with local storage, say if data are saved in local, we will not able to do it ?
  EBS is charged separately, the large local storage of 850GB might not be that advantageous ? Is EBS used normally for Webserver data or primary for MySQL for persistent data?</p>
  
  <p>Anyone who has experience with AWS can have good inside on this?
  That will mean that most of the instances i pay for have to buy EBS to enjoy the switch over capability?</p>