Welcome to ExamTopics
ExamTopics Logo
- Expert Verified, Online, Free.

Exam AZ-104 topic 4 question 14 discussion

Actual exam question from Microsoft's AZ-104
Question #: 14
Topic #: 4
[All AZ-104 Questions]

You plan to move a distributed on-premises app named App1 to an Azure subscription.
After the planned move, App1 will be hosted on several Azure virtual machines.
You need to ensure that App1 always runs on at least eight virtual machines during planned Azure maintenance.
What should you create?

  • A. one virtual machine scale set that has 10 virtual machines instances
  • B. one Availability Set that has three fault domains and one update domain
  • C. one Availability Set that has 10 update domains and one fault domain
  • D. one virtual machine scale set that has 12 virtual machines instances
Show Suggested Answer Hide Answer
Suggested Answer: C ūüó≥ÔłŹ
An update domain is a logical group of underlying hardware that can undergo maintenance or be rebooted at the same time. As you create VMs within an availability set, the Azure platform automatically distributes your VMs across these update domains. This approach ensures that at least one instance of your application always remains running as the Azure platform undergoes periodic maintenance.
Reference:
http://www.thatlazyadmin.com/azure-fault-update-domains/

Comments

Chosen Answer:
This is a voting comment (?) , you can switch to a simple comment.
Switch to a voting comment New
fedztedz
Highly Voted 2 years, 6 months ago
Answer is wrong. The correct Answer is A. First: in case you created on fault domain, you are limited with one update domain. You can test this. Second: By default, Azure uses 5 update domains and up to 3 fault domains. So, In case you created 10 vm in scale set. then you will have 2 vm in each update domain. So once one update domain is not available, then you get 4 domains with 8 vms as required.
upvoted 195 times
rupayan87
6 months, 2 weeks ago
you can have up to 3FD and 20UD. It can be any combination. 1FD x 10UD is also perfectly fine. You need to create 10VM and put them in AV Set. MS will distribute the VMs into UDs within the FD. During maintenance UDs are respected by MS
upvoted 6 times
...
ZacAz104
8 months, 3 weeks ago
Question says "during planned Azure maintenance" this has nothing to do with Scale set definition so i think C is correct we need Availability set nor Scale set
upvoted 19 times
...
kilowd
1 year ago
If A is correct why not D ..Atleast 8 means 8 or more..Even though 12 is an overkill the question does not specify any restriction with regards to Cost
upvoted 5 times
ConanBarb
3 months, 1 week ago
Incorrect. 12 VMs is not overkill - it will not meet the requirements of at least 8: VM spread over 5 UDs in a VMSS: 3, 3, 2, 2, 2
upvoted 1 times
...
Mr_Marcus
11 months ago
Given that either 10 or 12 VMs will do the job, cost efficiency would be implied when coming up with an answer. Good old Microsoft...
upvoted 3 times
ConanBarb
3 months, 1 week ago
Sorry but that is not a correct understanding of Update Domains. 12 VMs in a VMSS that will have 5 UDs by default will render the following VM spread over the UDs: 3, 3, 2, 2, 2. Hence when UD1 or UD2 is taken down for update there will only be 7 VMs running.
upvoted 2 times
ericZX
1 month, 1 week ago
If there are 12 VMs in a VMSS, when UD1 or UD2 is taken down for update there will only be 3+2+2+2=9 VMs running......
upvoted 2 times
...
...
...
ThatDowntownSmell
11 months, 2 weeks ago
Good point, either A or D would work. Make me wonder if this question is not copied or translated correctly.
upvoted 2 times
...
...
Dave03
7 months ago
You are giving incorrect explanation. Each availability set can be configured with up to three fault domains and twenty update domains.
upvoted 7 times
...
...
mlantonis
Highly Voted 2 years ago
Correct Answer: A VM Scale Set consists of a set of identically configured VMs. Availability Set consists of a set of discrete VMs. No more than 20% of the Scale Set upgrading at any time, then 2 machines out of 10 will have maintenance, the 8 remaining VMs will be up. Virtual machine scale sets are created with five fault domains by default in Azure regions with no zones. For the regions that support zonal deployment of virtual machine scale sets and this option is selected, the default value of the fault domain count is 1 for each of the zones. FD=1 in this case implies that the VM instances belonging to the scale set will be spread across many racks on a best effort basis. Reference: https://docs.microsoft.com/en-us/azure/virtual-machines/manage-availability 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
upvoted 183 times
UWSFish
1 month, 2 weeks ago
I agree with everyone here saying that answer C will do the job. I wouldn't get hunf up on that. The final line does not say, "which of these choices will meet the requirements". it says, "What SHOULD you create" (emphasis mine). Which of the options is cleanest, most elegant, way forward. Clearly A.
upvoted 1 times
...
garmatey
1 month, 4 weeks ago
What part of the question indicates if the VMs are identical or discrete?
upvoted 1 times
...
morito
2 months, 3 weeks ago
"Virtual machine scale sets are created with five fault domains by default in Azure regions" I believe you're speaking of update domains?
upvoted 3 times
...
...
Athul07
Most Recent 13 hours, 16 minutes ago
To ensure that App1 always runs on at least eight virtual machines during planned Azure maintenance, you should create: A. one virtual machine scale set that has 10 virtual machine instances. A virtual machine scale set (VMSS) allows you to deploy and manage a set of identical virtual machines that can automatically scale up or down based on demand. By creating a VMSS with 10 virtual machine instances, you ensure that there are always at least eight instances available even during planned Azure maintenance events. With a VMSS, Azure handles the maintenance operations by automatically distributing the updates across the virtual machine instances, ensuring that a minimum number of instances are always available to serve your application. Therefore, the correct answer is A. one virtual machine scale set that has 10 virtual machine instances.
upvoted 1 times
...
itguyeu
3 weeks, 5 days ago
Confusing, but should be C. "By default, Azure will assign three fault domains and five update domains (which can be increased to a maximum of 20) to the Availability Set. When spreading your VMs over fault domains, your VMs sit over three different racks in the Azure data center. What is the default number of update domains for an availability set? five update domains. When you create an availability set, Azure creates five update domains by default. These update domains are spread across the fault domains in the availability set.
upvoted 1 times
...
quocdunginfo2
1 month ago
C is the answer Keyword here is "at least 8 VMs during Azure maintenance", it should be "Avail Set" and "Update Domain" VMs in differ update domain will not be reboot at the sametime. In that case, we need at least 9 update domain in order to ensure at least 8 VM always running, so C is satisfied
upvoted 1 times
...
JunetGoyal
1 month ago
Exact same Q came in my exam on 30 April2023. My Ans A. as 20% goes at mainatnce if part of scaleset
upvoted 2 times
...
margotfrpp
1 month, 2 weeks ago
Selected Answer: C
VM have to be on different update domain
upvoted 1 times
...
Tinez
2 months, 1 week ago
Selected Answer: A
Answer is A.
upvoted 1 times
...
JunetGoyal
2 months, 1 week ago
Create scale set, put initial count 10 vm, A is right
upvoted 1 times
...
liza1234
2 months, 2 weeks ago
Very Correct Answer: D If you have 3 default FDs and 12 VMs running, then if 1 FD is down, then 4 VMs are down, leaving you with at least 8 more running VM's at any given time. At any given time that a planned maintenance happens, you will always have at least 8 running VMs if 1 fault domain is down.
upvoted 1 times
liza1234
2 months, 2 weeks ago
you can't go below 12 VMs. 12 VMs should be the minimum number if the default fault domain is 3 as that would take down 1/3 of the VMs when 1 fault domain is down.
upvoted 1 times
...
...
Tyrel
2 months, 3 weeks ago
Selected Answer: A
mlantonis has it right, it's A.
upvoted 1 times
...
GeeB1
2 months, 3 weeks ago
C is the one
upvoted 2 times
...
Gzt
2 months, 4 weeks ago
Selected Answer: C
Answer C
upvoted 3 times
...
Durden871
2 months, 4 weeks ago
For those struggling with the near 50/50 split. I myself said, "C"; however, I'm comparing ExamTopics with Udemy and Udemy disagrees with the answer as well along with an explanation.
upvoted 2 times
Durden871
2 months, 4 weeks ago
Explanation Correct Answer(s): one virtual machine scale set that has 10 virtual machines instances - A regional (non-zonal) scale set uses placement groups, which act as an implicit availability set with five fault domains and five update domains. If you have 10 VMs spread across five update domains, the 8 VMs will be available for any given Azure planned maintenance. https://docs.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-faq#do-scale-sets-work-with-azure-availability-sets Wrong Answers: one Availability Set that has three fault domains and one update domain ‚Äď We cannot create with one update domain. It should be 2 or more. one Availability Set that has 10 update domains and one fault domain ‚Äď We cannot create with one fault domain. It should be 2 or more. one virtual machine scale set that has 12 virtual machines instances ‚Äď This will create more VMs than required, thus increasing costs.
upvoted 4 times
Durden871
2 months, 4 weeks ago
And, to end this debate once and for all. Try actually doing it. You don't even need to create the VM, just start the process. I just did. "The update domain count must be 1 when fault domain count is 1."
upvoted 4 times
...
...
marcusw526
1 month, 1 week ago
Who did you ask at Udemy for the answer? I signed up with udemy but honestly started to feel like the classes were bullshit. I bought a class that said it was supposed to have labs included so I could get real practice but it ask to pay extra for them and my sponsor refuses to pay so I decided to come here instead of wasting my time watching videos.
upvoted 1 times
...
...
Doman01
3 months ago
The correct Answer will be A (can be D if we are not looking on costs), tested it with the portal and when I set FD to 1 I could not change UD to anything than 1 and got this message shown on screenshit https://imgur.com/a/x0yyWlk
upvoted 3 times
Doman01
2 months, 3 weeks ago
I am taking back what I said here There is no correct answer "during planned Azure maintenance." means UPDATE DOMAIN, when MS says that in documentation or other questions they are alsawys referring to UPDATE DOMAINS, if it would be "unplanned" it would be about FAULT DOMAINS, Scale Sets have nothing to do with it C is the best option but is wrong cause when you have 1 FAULT DOMAIN you can have only 1 Update domain (attached screenshot) so: A, D - WRONG, VMSS have nothing to do with this B - WRONG, we are talking about planned maintaince which refers to UPDATE DOMAINS C - BEST ASNWER BUT WRONG - 10 UPDATE DOMAINS would do the work but you cannot create them while having 1 FAULT DOMAIN https://imgur.com/a/uDFzSnw
upvoted 2 times
...
...
ConanBarb
3 months, 1 week ago
Selected Answer: C
Correct answer: C This was actually one of the more interesting and intriguing question! It really makes you think. First: Both A and C solve problem of guaranteeing 8 VMs running. Not B: only one UD here, i.e. all could/will go down during planned host maintenance Not D: 12 VMs over 5 UDs, means two UDs will have 3 VMs each hence 7 VMs could end up running. So why C over A? Well first the question actually says "App1 will be hosted on several Azure virtual machines." This can be interpreted as several ("discrete") VMs, i.e. a VMAS and not VMSS which run the same VM in several instances. But mostly C over A due to the fact this scenario is about availability, i.e. creating redundant resources when things go down, and not scalability, i.e. creating redundant resources for performance reasons.
upvoted 4 times
Durden871
2 months, 4 weeks ago
Have you tried this in a lab? I just did and the answer cannot be "C". The answer specifically states "1 fault domain". When you try to set it up in a lab you get the following error message: "The update domain count must be 1 when fault domain count is 1." Thus, the answer is "A."
upvoted 1 times
...
...
Takate
3 months, 2 weeks ago
For Planned maintenance azure uses Update Domain, So C is correct answer
upvoted 2 times
...
Community vote distribution
A (35%)
C (25%)
B (20%)
Other
Most Voted
A voting comment increases the vote count for the chosen answer by one.

Upvoting a comment with a selected answer will also increase the vote count towards that answer by one. So if you see a comment that you already agree with, you can upvote it instead of posting a new comment.

SaveCancel
Loading ...