In my previous post, I had explained about the high availability configuration for Azure virtual machines, Availability Sets, Fault domains and Update domains. In this blogpost, I’ll cover step-by-step configuration using Azure Portal. Availability Set configuration can be done in two ways, either by creating and configuring it in early stage based on your application architecture or set it up while creating a first VM for each tier and add rest of the same tier VMs to the respective availability set.
I am going to explain, how to create and configure availability set in advance.
Login to the Azure Portal and select “+ Create a resource”.
In the Azure Market Place, search for Availability Set.
From the search results, select “Availability Set”.
In the Availability Set panel, select create.
In the create availability set panel, define the parameters.
Name: Enter the name of the availability set.
Subscription: Select the subscription.
Resource group: Either create a new one or select an existing one based on your requirement.
Location: Select the location.
Fault domains: Select the number of fault domains, by default it is two but for specific Azure regions you can select up to three fault domains.
Update domains: Select the number of update domains, by default it is five but you go up to 20 update domains in each availability sets.
Use managed disks: Select Yes (by default) if you would like to use managed disk for all the VMs that will be create in this availability set otherwise “No”.
Once, you have filled all the details based on your requirement then select “create” to start the deployment of availability sets.
Wait for few seconds, your availability set will be created. Now, you can go head and create your VMs using this availability set.
While creating a virtual machine you get both the options, either select the existing availability set or create a new one.
If you select the “+ Create new” then again you have to fill the same details as filled earlier then select “OK”.
Once you created an availability set, you will not able to modify it and the same concept applies to VM as well. If you have created a VM as part of the availability set then you can’t come out or change the availability set until you delete and recreate it.