title: Azure Availability sets vs. Availibility Zones
body: <p>Azure offers <a href="https://social.technet.microsoft.com/wiki/contents/articles/51828.azure-vms-availability-sets-and-availability-zones.aspx" rel="nofollow noreferrer">two different availability solutions</a>:</p>
  
  <p><strong>1. Availability Sets</strong></p>
  
  <blockquote>
    <p>A group with two or more virtual machines in the same Data Center is called Availability Set, this ensures that at least one of the
    virtual machines hosted on Azure will be available if something
    happens. This configuration offers 99.95% SLA.</p>
  </blockquote>
  
  <p><strong>2. Availability Zones</strong></p>
  
  <blockquote>
    <p>... Virtual Machines are in different physical locations within an Azure Region. ... Availability zones offer 99.99% SLA.</p>
  </blockquote>
  
  <p>Not all services support <a href="https://docs.microsoft.com/en-us/azure/availability-zones/az-overview" rel="nofollow noreferrer">Availability Zones</a>.</p>
  
  <p><strong>My Question</strong></p>
  
  <p>So Availability Zones seem to be the superior solution: Higher SLA at the same price. Are there any reasons why I should choose Availability Sets if Availability Zones are supported?</p>