Tuesday, August 27, 2013

Windows Azure Virtual Machine Single instance scheduled maintenance


Dear Customer,

Upcoming maintenance will affect single instance deployments of Windows Azure Virtual Machine….”impact single instance deployments of Virtual Machines that are not using availability sets…”

When do i have problems? in the weekend? Nope…during the week!image

What is my problem, roles, temporary storage, reboots?

  • Temporary storage?



  • Roles

“Please note that Cloud Services using Web or Worker roles aren’t impacted by this maintenance operation. “


  • Reboots

“Single instance virtual machine deployments that are not in availability sets will reboot once during this maintenance operation. “


So….i need an availability set!

  • Aiai…do i have one? Go to your virtual machine, ‘Configure’ and determine if any availability sets are mentionedimage


  • If this is not the case, we need to create an availability set, this is very easy, select ‘Create an Availability set’ and type in a name' (note: the machine must be running!)


  • Click Save and confirm



  • Watch the magic happen


  • Verifying the machine state


So…..what is happening, what is going to happen when i create a availability set?

  • The state of the machine will be persisted to disk
  • A copy of this disk will be stored in your Blog Storage container
  • Another Machine will be instantiated (with the name of your Availability set)
  • This machine will be running and will be used as the ‘switchover’ machine when Faults are detected/Updates are performed



So….we are basically achieving high availability! I want to know more….

  • Some slides (see this page below for reference), with some additional explanational, graphical view on the inner workings


  • How does this relate to the Azure Data center?


  • What components are in place, to detect these faults, ensures that everything works? Say hallo to "Fabric Controller”

The concept of fabric in Microsoft’s implementation in production exhibits itself in the so-called Fabric Controller or FC which is an internal subsystem of Windows Azure. FC, also a distribution point in cloud, inventories and stores images in repository, and:

  • Manages all Compute and Storage resources
  • Deploys and activates services
  • Monitors the health of each deployed service
  • Provisions the necessary resources for a failed service and re-deploys the service from bare metal, as needed



It’s amazing what happens underneath when you click through the portal, or when you are deploying a service into the cloud!


  • See more detailed deep dive material on the inner workings here;





For now….i’m safe and happy with my availability set, and learned a lot doing it as well Glimlach.




1 comment:

Robertson White said...

Hi, thanks for this very nice and interesting post. I like your writing style, it’s quite unique.