Free Nutanix NCSE-Core Practice Exam with Questions & Answers | Set: 6

In an 8-node hybrid cluster configured with a Fault Tolerance level of 2 (RF3), the system can tolerate up to two simultaneous failures. However, if there are SSD failures on two different nodes and a CVM is powered off on another node simultaneously, the data availability is compromised. This combination results in losing the quorum necessary for maintaining data availability and integrity, leading to VM data becoming unavailable.

References:

Nutanix Bible

When an HA event causes a SQL virtual machine to restart on a different node, Nutanix's data locality feature ensures that the active VM data is localized to the new node. This means that the data associated with the VM will be migrated to the storage local to the new node, ensuring optimal performance by reducing the need for cross-node data access.

References:

Nutanix Bible​

Compared to a traditional 3-tier architecture, Nutanix offers the following benefits:

Elimination of Siloed Storage:

Nutanix consolidates file, block, and object storage into a single platform, eliminating the need for separate, siloed storage systems. This simplifies management and improves resource utilization.

Avoidance of Generational Infrastructure Silos:

Nutanix's modern lifecycle management allows for seamless upgrades and expansions, avoiding the creation of generational silos. This ensures that the infrastructure remains up-to-date and can easily adapt to new technologies and requirements without disruptive forklift upgrades.

References:

Nutanix Bible​

Zookeeper in Nutanix is responsible for distributing metadata to ensure availability in case of node or block failure. Metadata includes important information about the state and configuration of the cluster, which is crucial for maintaining cluster operations and consistency.

References:

Nutanix Bible

For deploying 5000 virtual desktops in an active/active deployment that ensures availability during maintenance or disasters, the minimum number of nodes required is 104. This configuration accounts for high availability and redundancy, ensuring that the virtual desktops remain operational even if an entire site becomes unavailable​​.

To ensure the solution does not exceed 80% CPU utilization when a node is placed in maintenance mode, the SE should:

Access Sizer: Open the Nutanix Sizer tool.

Create New Scenario: Start a new scenario for the project.

Define Workload: Enter the details of the current workload, specifying resource requirements.

Customize CPU Threshold:

In the sizing options, customize the CPU threshold to 80%. This setting ensures that the calculated resources account for keeping CPU utilization at or below 80% when a node is taken out of the pool for maintenance (N+0).

Review Configuration: Verify that the proposed configuration meets the 80% CPU utilization requirement under maintenance conditions.

This approach ensures that the solution is appropriately sized to handle the specified workload without exceeding the desired CPU utilization threshold.

References:

Nutanix Sizer documentation and guides.

Best practices for configuring CPU thresholds and resource allocation.

The ADS (Acropolis Dynamic Scheduler) service in AHV performs the following tasks for VMs:

Invokes workload movement if there is contention of resources: ADS dynamically reallocates resources to balance the load and prevent resource contention.

Balances VMs throughout the cluster when the VM is first powered on: ADS ensures that VMs are optimally placed based on available resources and load distribution when they are started​​.

Current Configuration:

The customer has a 3-node cluster configured for RF2 with 100TB of raw disk space.

Erasure Coding Requirements:

Erasure Coding (EC-X) improves storage efficiency by using a parity-based method to store data.

For EC-X to be enabled, a minimum of 4 nodes is required in the cluster.

Explanation:

RF2 (Replication Factor 2): Requires data to be replicated across at least two nodes.

Erasure Coding: Requires additional nodes beyond the replication factor to store parity information. In this case, a minimum of 4 nodes is needed to implement EC-X.

Required Change:

Add 1 Node: Adding one more node to the existing 3-node cluster will meet the minimum requirement of 4 nodes, allowing the customer to enable Erasure Coding.

Outcome:

By adding an additional node, the cluster will be able to utilize Erasure Coding, thereby gaining additional usable space.

Scenario Analysis:

The VM is protected with NearSync Replication, scheduled every 15 minutes, but misses the replication window during nightly backups due to high write volumes.

Expected Behavior:

Option B: Protection Domain transitions back to hourly schedule:

NearSync automatically falls back to a less frequent replication schedule, such as hourly, when it cannot keep up with the 15-minute schedule due to write volume or other issues.

Option D: The system continuously tries to get to the NearSync schedule:

The system does not give up on the NearSync schedule. Instead, it keeps attempting to return to the 15-minute interval as soon as conditions allow (e.g., write volume decreases)​​.

Behavior Explanation:

Hourly Schedule Transition:

When the high write volume prevents the 15-minute replication, NearSync transitions to an hourly schedule to ensure that replication continues, albeit at a reduced frequency.

Continuous Attempt to Return to NearSync:

The system monitors conditions and makes continuous efforts to revert to the NearSync schedule as soon as it becomes feasible.

Conclusion:

The correct options that describe the expected behavior are B and D.

References: Nutanix Bible explanation of NearSync behavior under high write volumes and missed replication windows.