AZ-104 Practice Question 45: VM Resize Availability Set
Microsoft Azure Administrator Associate (AZ-104) · Test 5 · question 5 of 10
Three VMs run in one availability set. You need to change one of them from Standard_D4s_v3 to Standard_E8s_v5 because the workload has become memory-bound.
With the VM running, you open Size in the portal and Standard_E8s_v5 is not in the list. The size is generally available in the region and your subscription has quota for it.
What should you do?
Show answer and explanation
Answer:
The size list shows what the VM's current hardware can offer: "deallocation may be required if the new size isn't available on the hardware cluster currently hosting the VM", and "if your VM is still running and you don't see the size you want in the list, stopping the virtual machine may reveal more sizes." The availability set adds the second half: "if the new size for a VM in an availability set isn't available on the hardware cluster currently hosting the VM, then you need to deallocate all VMs in the availability set to resize the VM." Plan for downtime either way, even when deallocation isn't required, "changing the size of a running VM will cause it to restart", and note that deallocating "releases any dynamic IP addresses assigned to the VM", while the disks are unaffected.
Option A describes something Azure does not do for a resize. There is no live migration onto a different cluster to satisfy a size change; that is precisely why the size is missing from the list.
Option B is unnecessary work built on a false premise. Resizing across size families is supported; what constrains it is cluster capacity, plus specific documented limits such as moving between sizes with and without a local temp disk on Windows.
Option C confuses management grouping with placement. Moving a resource to another resource group is a Resource Manager metadata operation; it does not deallocate the VM or change the cluster it runs on.
Reference: Resize a virtual machine