You have an Exchange Server 2013 organization that contains the servers configured as shown in the
following table.
All of the Exchange servers run Windows Server 2012 R2 and are members of a database availability
group (DAG) named DAG1. Each server has a copy of all the mailbox databases. DAG1 is configured
to have a cluster administrative access point. The file share witness is located in Site A.
EX5 fails and is taken offline permanently.
You need to identify the maximum number of Mailbox servers that can fail simultaneously without
affecting the mailbox access of the users.
How many servers should you identify?
A.
2
B.
3
C.
4
D.
5
The answer is D. 5
You can go down to one server and continue to provide mailbox access in this scenario.
In Windows Server 2012, as an advanced quorum configuration option, you can choose to enable dynamic quorum management by cluster. When this option is enabled, the cluster dynamically manages the vote assignment to nodes, based on the state of each node. Votes are automatically removed from nodes that leave active cluster membership, and a vote is automatically assigned when a node rejoins the cluster. By default, dynamic quorum management is enabled.
With dynamic quorum management, it is also possible for a cluster to run on the last surviving cluster node. By dynamically adjusting the quorum majority requirement, the cluster can sustain sequential node shutdowns to a single node.
Reference:
https://technet.microsoft.com/en-us/library/jj612870.aspx#BKMK_dynamic
http://exchangeserverpro.com/windows-server-2012-dynamic-quorum/
Reference: Managing database availability groups
https://technet.microsoft.com/en-us/library/dd298065%28v=exchg.150%29.aspx
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Nothing mentioned about dynamic quorum, but yes it is on by default with server 2012… looks you are right. One more vote for “D”
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In this case we have to change answers of questions 140 and 138 too, but there is no suitable answer if we assume dynamic quorum is enabled. Probably something missing in question or if nothing mentioned about dynamic quorum means that is not on!
I will go with “A”!
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It has NOTING to do with DQ. DQ only works with sequential failure NOT simultaneous failure! Search it on Technet. Or search for Teched on Youtube.
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I guess the difference is “fail” or “maintenance”, it is different for cluster if node fails or is properly shutdown.
Here it is about fail. And dont forget witness.
Starting position – 7 nodes and witness
EX5 fails – 6 nodes and witness
How many more can fail? it is majority of 7 votes to maintain quorum, so I guess 3 more can fail – answer B.
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I agree with Anna.
The key term in the question is “fail simultaneously”. Dynamic Quorum will not help when multiple nodes fail at the same time. Dynamic quorum only helps when you have cascading failures.
Dynamic quorum has already taken effect when we lost EX5. We now have 6 servers online + one witness. This gives us a total of 7 votes for quorum, with 4 servers required to be running to give us a majority vote. The maximum servers that can fail simultaneously is then 3.
The answer is B – 3 servers can fail simultaneously.
After this, dynamic quorum would kick in and we could handle more failures, but this is outside the question scope.
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Agree
6 server /2 = 3 server votes + 1 vote FSW = 4 and that’s +50% for quorum.
I go for answer 3.
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https://technet.microsoft.com/en-us/library/dd979799%28v=exchg.150%29.aspx
“Quorum requires a majority of voters to be able to communicate with each other. Consider a DAG that has four members. Because this DAG has an even number of members, an external witness server is used to provide one of the cluster members with a fifth, tie-breaking vote. To maintain a majority of voters (and therefore quorum), at least three voters must be able to communicate with each other.”
In our situation: 1 FWS + 2 exchange servers from site A, thus, my answer C (4)
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SORRY!
By dynamically adjusting the quorum majority requirement, the cluster can sustain SEQUENTIAL NODE SHUTDOWNS down to a single node and still keep running. “It does not allow the cluster to sustain a simultaneous failure of a majority of voting members!”
I changed my mind after a while looking around, i’m also going with B(3)
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