Availability Set Archives - SIOS SANless clusters

Changing The Availability Set Of An Existing Azure VM

6/21/2016 – Update. Since I posted this article I have been told by a reliable source that there is a newer PowerShell script that could Change Availability Set Of Existing Azure VM even more reliably. I haven’t tried it yet. But I trust the source and Microsoft Premiere Support directed him to this article. https://gallery.technet.microsoft.com/Azure-RM-Availability-Set-39e19d01

I was a little surprised to find out today that it is not easy to change what Availability Set a VM resides in once it is already created. The Azure portal has no mechanism of adding an existing VM to an Availability Set. Fortunately for me I stumbled upon this great resource.

By leveraging the PowerShell script available for download in that article I was able to add two existing VMs to what I had created. Finally I could Change Availability Set Of Existing Azure VM – what a life saver!

Change Availability Set Of Existing Azure VM

Three Fault Domains In Azure Now Default When Using Resource Manager Deployment Model

Lo and behold, I was extremely happy to see a change – Three Fault Domains! After being away from Azure for a month or two this summer I decided fire up the Azure Portal. I wanted to see what changes have been implemented recently as I prepare for my PASS presentation on Azure SQL Server high availability. They have finally started offering Three Fault Domains per Availability Set as the default setting. Choose “Resource Manager” as your deployment model instead of “Classic”.

Up until now when you created an Availability Set, the default option was to create two Fault Domains per Availability Set. When deploying a cluster, it is important to have a minimum of three Fault Domains. One for each cluster node and one for your File Share Witness. This ensures that a failure of a single fault domain never impacts more than one of your quorum votes at any given time. Before this feature was implemented in the GUI, there was a way to do it through an ARM Template. But putting it in the GUI makes it easy for those administrators not quite up to speed on ARM templates.

This feature now completes the steps I documented earlier on how to create a SQL Server FCI in Azure.

Three Fault Domains In Azure Now Default When Using Resource Manager Deployment Model