Exam AZ-104 topic 3 question 27 discussion

Correct Answer: D When you create an Availability Set, the hardware in a location is divided into multiple update domains and fault domains. An update domain is a group of VMs and underlying physical hardware that can be rebooted at the same time. VMs in the same fault domain share common storage as well as a common power source and network switch. During scheduled maintenance, only one update domain is updated at any given time. Update domains aren't necessarily updated sequentially. So, we need two update domains. Reference: https://docs.microsoft.com/en-us/azure/virtual-machines/windows/tutorial-availability-sets https://docs.microsoft.com/en-us/azure/virtual-machines/manage-availability https://docs.microsoft.com/en-us/azure/virtual-machines/maintenance-and-updates

It's "planned maintenance of the HARDWARE" in the question, not OS or software update. Should be 2 fault domains imho.

Correct answer is still D. In case there is any confusion, update domains are for “planned”maintenance. https://docs.microsoft.com/en-us/azure/virtual-machines/windows/tutorial-availability-sets https://docs.microsoft.com/en-us/azure/virtual-machines/manage-availability https://docs.microsoft.com/en-us/azure/virtual-machines/maintenance-and-updates

D is corerct

when hardware failure, fault domain need to use. If update such as windows update that require system reboot, update domain is use. So it should be fault tolerance I blv.

The correct answer is: B. Two fault domains. Explanation: An availability set in Azure is a way to ensure high availability of applications by distributing them across multiple distinct physical servers called fault domains. Each fault domain shares a common underlying infrastructure, such as power and cooling, but is isolated from other fault domains. Thus, if an issue occurs in one of the fault domains, the other domains remain operational, ensuring the continuous availability of applications. In this case, by having two fault domains, the availability set will ensure that App1 remains available during planned maintenance of the hardware hosting VM1 and VM2.

D is right

This question was in exam 01/03/2024

Fault Domains = Physical Rack sharing power and network. Unplanned maintenance. Max 3 Update Domains = Logical grouping of virtual machine. Allows restarts/planned maintenance. Max 20. Ref: https://youtu.be/BGcKAXMBmcs?si=1-aPQzYi1wQ-DRbG

keywords: planned maintenance. "The order of update domains being rebooted may not proceed sequentially during planned maintenance, but only one update domain is rebooted at a time." https://learn.microsoft.com/en-us/azure/virtual-machines/availability-set-overview#how-do-availability-sets-work

Found this Q in the exam, 3/7/2023

I think MS needs to merge these 2 because they create confusion. If a system is down, then it's down and can't serve your customers. The reason is irrelevant, be it maintenance or an unexpected failure of whatever nature. In concept, update and failure domains should coincide.

Fault domains represent separate racks in the data center and protect against single points of failure. Update domains protect against planned maintenance and software updates. It is best practice to place VMs across multiple fault domains and update domains for the highest level of availability. Therefore, in this scenario, including two fault domains in the Availability Set will ensure that the application remains available during planned maintenance of the hardware hosting VM1 and VM2.

Cleared Exam today 26 Feb, This question was there in exam.

D is the answer. https://learn.microsoft.com/en-us/azure/virtual-machines/availability-set-overview#how-do-availability-sets-work Update domains indicate groups of virtual machines and underlying physical hardware that can be rebooted at the same time. When more than five virtual machines are configured within a single availability set with five update domains, the sixth virtual machine is placed into the same update domain as the first virtual machine, the seventh in the same update domain as the second virtual machine, and so on. The order of update domains being rebooted may not proceed sequentially during planned maintenance, but only one update domain is rebooted at a time. A rebooted update domain is given 30 minutes to recover before maintenance is initiated on a different update domain.

Passed today on 29Jan23 with a score of 970. This question was in the exam. Correct Answer: D. two update domains

D) "two update domains" To assure that during planned maintenance at least 1 VM is still operational, 2 Update Domains need to be created. Each VM will be in its respective Update Domain.