title: Setting up High Availability on Azure
body: <p>We are in the process of moving our current IAAS solution over to azure where we host asp.net LOB web applications in IIS with an SQL Server backend. </p>
  
  <p>I’m looking into availability sets. I stumbled upon this article at: <a href="http://michaelwasham.com/windows-azure-powershell-reference-guide/understanding_configuring_availability_sets_powershell/" rel="nofollow noreferrer">http://michaelwasham.com/windows-azure-powershell-reference-guide/understanding_configuring_availability_sets_powershell/</a></p>
  
  <p><img src="https://i.stack.imgur.com/6f0bo.png" alt="High Available Setup"></p>
  
  <p>This seems like how we want to setup our deployment on Azure where the “Web Servers” are our virtual machines. My question relates to how we setup our virtual machines. Currently we have about 200 separate hosted customers on our IAAS solution which means 200 separate web applications in IIS. With a highly available deployment should the Virtual machines be exact replica’s of each other i.e. 200 customers on box 1 and that again on box 2. Or should we spread them over multiple boxes i.e. 0-50 customers on box 1, 50-100 customers on box 2 and so on. </p>
  
  <p>I cant see how the 2nd option spread would work in a highly available set because if 1 box goes down than all the customers on it go down with it?</p>
  
  <p>Little confused, hoping someone has got advice on this?</p>
  
  <p>Thanks</p>