Nutanix Certified Associate Practice Exam

What configuration change should be made to ensure an RF3 cluster can survive a failure of two racks?

1. Expand the cluster to 48 nodes distributed evenly across 6 racks.

2. Expand the cluster to 60 nodes distributed evenly across 6 racks.

3. Expand the cluster to 40 nodes distributed evenly across 5 racks.

4. Expand the cluster to 50 nodes distributed evenly across 5 racks.

The correct answer is: Expand the cluster to 60 nodes distributed evenly across 6 racks.

To ensure that a Replication Factor 3 (RF3) cluster can survive a failure of two racks, the chosen configuration needs to account for both data availability and redundancy. RF3 means that three copies of each piece of data are stored across different nodes. When expanding to a total of 60 nodes distributed evenly across 6 racks, each rack would contain 10 nodes. This setup would enable the cluster to tolerate the failure of two entire racks while still maintaining data availability. Since there are three copies of every piece of data, losing two racks (which have 20 nodes total) doesn't compromise the ability to access data, as there would be sufficient remaining nodes (40 nodes) across the remaining racks to still provide the necessary copies. In contrast, expanding to the other options might not provide the same level of resilience. For example, if the cluster were expanded to fewer nodes or racks, there could be scenarios where the loss of two racks would lead to a situation where some data would not have enough copies remaining for access, violating the requirements of RF3. Therefore, the configuration of 60 nodes allows for adequate distribution and redundancy to handle two rack failures effectively.