Exam AZ-104 topic 4 question 57 discussion

Correct Answer: Box 1: 4 If you resize the Scale Set all the VMs get resized at once, thus 4 is the correct answer. Box 2: 1 Automatic OS updates update 20% of the VMs at once, with a minimum of 1 VM instance at a time. Also 20% of 4 = 0.8. Reference: https://docs.microsoft.com/en-us/learn/modules/build-app-with-scale-sets/2-features-benefits-virtual-machine-scale-sets https://docs.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-automatic-upgrade https://docs.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-upgrade-scale-set

The question asks "if the administrator changes the size", not if it gets scaled up vertically. I tested this, and if you resize the scale set all the virtual machines get resized at once, thus 4 is the correct answer. For the second part, automatic OS updates update 20% of the VMs at once, with a minimum of 1 VM instance at a time.

what if the orchestration mode of the VMSS is not uniform, it's flexible?

1) 4 VM 2) 0 VM. EnableAutomaticUpdate is set to false. So this setting prevent Automatic Update of the OS for the VM inside the VSS, even if the UpgradePolicy is set to Automatic.

enableAutomaticUpdates = false , so its 0.

You can resize VM in VMSS config. Only the one specific VM will be resized, not whole scale set. Box1 :1 Box2 :1

Final Answer : 4 1

Box 1: 1 This is because the question 1 states : " if the administrator changes the size of a VM (in the scaleset)" It is not resizing the scaleset. AI answer to this is as follows: Resizing an Individual VM: When you change the size (SKU) of an individual VM within the VMSS (e.g., from a smaller size to a larger one), only that specific VM is resized. The other VMs in the VMSS remain unaffected. The resized VM may need to be restarted to apply the new size. In summary, resizing an individual VM within a VMSS does not automatically resize all VMs in the set. You’ll need to manage each VM’s size independently. So the answer is 1 for Box 1. Box 2= 1 Automatic OS updates update 20% of the VMs at once, with a minimum of 1 VM instance at a time. Box 2 = 1

EnableAutomaticUpdates = FALSE: New Windows OS update must be done manually => 0 VM UpgradePolicy = Automatic: 20% of VMs will be upgrade at the same time (Min=1) => 1 VM

Newbee here, where can I know the total number of VMs?

Box 1: 4 & Box 2: 1

Guys, sorry for the noob question. where did you get the value "4"? I don't see any number 4 in the picture.

Box1 - 4 This refers to the second PS cmdlt 'UpgradePolicy' which "determines what happens next after you change the scale set model" (ex. VM size, OS ver, extensionPolicy). Box1 asks what happens when size of VM changes. Since it's set to 'automatic', the change will be applied to all the VMs in the scale set at once [ref: https://msftstack.wordpress.com/2016/11/15/azure-scale-set-upgrade-policy-explained/] Box2 - 0 This refers to the first PS cmdlt 'UpgradePolicy' which "determines what happens when image publishers publishes the latest image OS image - which in this case Microsoft released the Win Server 2016 image. Since it's set to 'false', there will be no changes made- u[dates will need to happen manually with user intervention. [ref: https://techcommunity.microsoft.com/t5/azure-paas-blog/azure-service-fabric-enableautomaticupdates/ba-p/834246]

It seems to me that picture doesn't match questions.

Box 1: 4 The first command has nothing to do with VM Resizing. Box 2: 1 What's set to 'false' is Patch updates. This is recommended to be set to 'False' when Automatic OS upgrades are set to 'True'. What this means is that the automatic rolling OS Upgrades will happen at 20%.

WindowsConfiguration.EnableAutomaticUpdates PropertyGets or sets indicates whether Automatic Updates is enabled for the Windows virtual machine. Default value is true. For virtual machine scale sets, this property can be updated and updates will take effect on OS reprovisioning. Based on the above note, as EnableAutomaticUpdates = False the OS updates will not happen. So answers are Box1: 4 and Box 2: 0

There're seven more confusing comments here, I am totally lost... as usual, I will follow the answer from mlantonis