70-663 Question #179: Real Exam Question with Answer & Explanation

Question

Exhibit

Options

• ANo file share witnesses are necessary.
• BPlace one file share witness in the Seattle datacenter.
• CPlace one file share witness in the Seattle datacenter and one alternate file share witness in
• DPlace one file share witness in the Dallas datacenter.

Explanation

Placing the file share witness in Dallas will ensure that Miami can maintain quorum if the Seattle site goes offline and vis-versa Here we have two DAG members; thus two voters. Using the formula V/2 + 1, we need at least 2 votes to maintain quorum. When the WAN connection between Miami and Seattle is lost, it causes the DAG's underlying cluster to verify that it still has quorum. In this example, the DAG member in Miami is able to place an SMB lock on the witness.log file on the Witness Server in Dallas. Because the DAG member in Miami is the locking node, it gets the weighted vote, and now therefore holds the two votes necessary to retain quorum and keep its cluster and DAG functions operating. Although the DAG member in Seattle can communicate with the Witness Server in Dallas, it cannot place an SMB lock on the witness.log file because one already exists. And because it cannot communicate with the locking node, the Seattle DAG member is in the minority, it loses quorum, and it terminates its cluster and DAG functions. Remember, it doesn't matter if the other DAG members can communicate with the Witness Server; they need to be able to communicate with the locking node in order to participate in quorum and remain functional. misconceptions-addressed.aspx

No community discussion yet for this question.