Question 16 : You work for a company named ABC.com. Your role as Cloud Administrator includes the management of the company's public and private cloud infrastructure. You have applications and virtual machines hosted on Windows Azure. An application hosted in Azure Cloud Services provides a web-based portal that is used by all company employees and selected customers. Two instances of a virtual machine (VM) running in Windows Azure perform back-end functionality for the portal application.

The portal application sometimes fails due to cloud services outages. You want to ensure that the virtual machines (VMs) are deployed to separate fault domains to ensure that the portal application remains available during network failures, local disk hardware failures, or any planned downtime. Which of the following actions will ensure that the VMs are in separate fault domains?

  1.      Adding the VMs to an Availability Set.

  2.      Adding the VMs to separate Availability Sets.

  3.      Adding the VMs to an Affinity Group.

  4.      Adding the VMs to separate Affinity Groups.

Correct Answer : 1 Exp  : Understanding and Configuring Availability Sets

You should ALWAYS specify an availability set when creating more than one virtual machine for the same purpose. 

Examples: 

Two or more web servers

Two or more SQL servers

Two or more AD servers

you get the idea

Specifying an availability set in these situations gives you multiple advantages. Highly Available Hardware

Putting two or more VMs in availability sets guarantees that your VMs are spread across multiple racks in the Windows Azure Data Centers. This means redundant power supply, switches and servers.

Rolling Host Updates Grouping VMs in availability sets also gives the Windows Azure Fabric Controller the information it needs to intelligently update the host OSs that your guest VMs are running on. Without availability sets the FC would have no idea that two machines were serving the same purpose and could reasonable take them both down for host OS updates.

99.95% SLA If you wish to have the 99.95% SLA guaranteed by Windows Azure for uptime using availability sets is the way to achieve it.