Nutanix NCP-MCI-6.10 - Nutanix Certified Professional - Multicloud Infrastructure (NCP-MCI v6.10)

Nutanix AHV networking documentation explains that high-connection-count workloads can saturate a single network queue, causing receive-side bottlenecks. VirtIO-Net supports Multi-Queue with Receive-Side Scaling (RSS), allowing the VM to distribute packet processing across multiple vCPUs. The documentation states, “Enabling RSS Multi-Queue improves performance for workloads handling a large number of simultaneous network flows by parallelizing packet handling.”

Trunk mode does not solve per-queue packet processing limitations. Adding vNICs is not recommended because the bottleneck is at the queue level, not the number of interfaces. Using the e1000 adapter results in lower performance compared to VirtIO and is discouraged. Therefore, enabling RSS Multi-Queue is the correct performance optimization for a VM handling thousands of client connections.

For Disaster Recovery to function correctly, the source and destination storage containers must have identical names.

Option C (Storage container name mismatch) is correct:

If thestorage container name at the DR site does not match, Nutanix cannot mapsnapshots and replication data.

This causesfailover operations to fail, even though data exists.

Option A (NGT not installed) is incorrect:

NGT is needed for application-consistent snapshots, butnot required for crash-consistent snapshots.

Option B (Windows updates) is incorrect:

OS updates do not affect replication availability.

Option D (Storage RF factor mismatch) is incorrect:

Replication works across different RF factors, but performance may vary.

In Nutanix AHV-based clusters, when you want to ensure that a specific VM (e.g., a critical VM like a domain controller) is powered on before other VMs during a host startup or failover scenario, you use the Agent VM configuration setting.

Here’s the exact explanation from the Nutanix ECA course:

“Agent VMs are special VMs that are automatically powered on before other user VMs during host startup or recovery. This ensures that critical VMs, such as those that provide essential services, are always available first.”

In contrast:

✅Recovery Plan (A) — This is used in the context of DR and failover, typically with Nutanix Leap.

✅Host Affinity (B) — Host affinity rules control placement policies of VMs but not startup priority.

✅High Availability (C) — HA ensures VMs are restarted on surviving hosts but does not control startup order.

Therefore, setting the VM as an Agent VM guarantees that it is powered on before the other VMs during host start-up. Let me know if you’d like steps on how to configure an Agent VM within Prism Central or Prism Element!

Nutanix storage container configuration guidance specifies that “Advertised Capacity” is the setting used to define a maximum limit for the container. This value enforces a hard cap on space usage. Reserved Capacity, in contrast, defines a minimum guarantee of space for the container and does not limit growth.

Prism Element is the correct interface for creating storage containers with specific data reduction settings such as compression and deduplication, as the container-level storage policies are applied directly at the cluster’s storage layer.

The documentation further clarifies that RF1, inline compression, and deduplication settings are configured within Prism Element under container creation. Therefore, to enforce the 100 GiB limit, the administrator must create the container in Prism Element and set the Advertised Capacity to 100 GiB.

Understanding the Issue

The administrator is investigating VM performance complaints and is analyzing CPU Ready Time data.

CPU Ready Time is a crucial metric in Nutanix and virtualization environments (AHV, ESXi, or Hyper-V).

It measures the amount of time a VM is waiting for CPU scheduling due to resource contention.

High CPU Ready Time indicates that VMs are ready to run but are waiting because the host lacks available CPU resources.

Analysis of the Exhibit

The graph shows CPU Ready Time spikes for multiple VMs.

Some VMs have CPU Ready Time exceeding 18% to 21.5%, which is very high.

A healthy CPU Ready Time should be below 5%.

Values above 10% indicate CPU contention, and anything above 20% is critical and requires immediate troubleshooting.

Evaluating the Answer Choices

❌(A) Check the number of vCPUs assigned to each CVM. (Incorrect)

CVMs (Controller VMs) have fixed CPU allocation, and modifying their vCPU count is not recommended unless advised by Nutanix Support.

The issue is related to VM CPU contention, not CVM configuration.

✅(B) Review host CPU utilization. (Correct Answer)

High CPU Ready Time suggests CPU overcommitment or host saturation.

The administrator should check host CPU usage in Prism Central to determine if the cluster is overloaded.

If host CPU usage is consistently above 85–90%, VMs are competing for CPU resources, leading to high CPU Ready Time.

❌(C) Assess cluster SSD capacity. (Incorrect)

SSD capacity impacts storage performance (latency, read/write speeds) but does not affect CPU Ready Time.

High CPU Ready Time is a CPU scheduling issue, not a storage bottleneck.

❌(D) Enable VM memory oversubscription. (Incorrect)

Memory oversubscription does not impact CPU scheduling.

Enabling memory oversubscription affects RAM allocation, but CPU Ready Time is strictly related to CPU contention.

Next Steps to Diagnose & Resolve the Issue

Review Host CPU Utilization:

Navigate to Prism Central → Analysis → CPU Usage per Host.

Identify hosts experiencing high CPU load.

Check VM vCPU Allocation:

Ensure that VMs do not have excessive vCPUs assigned, which can lead to scheduling inefficiencies.

Overprovisioning vCPUs can cause unnecessary contention.

Balance Workload Across Hosts:

Use Nutanix AHV DRS (Dynamic Scheduling) or VMware DRS to redistribute VMs across hosts.

Check if certain hosts are overloaded while others have spare CPU capacity.

Consider Scaling Out the Cluster:

If CPU usage is consistently high, adding more nodes may be required to reduce CPU contention.

Multicloud Infrastructure References & Best Practices

CPU Ready Time Best Practices:

Keep CPU Ready Time below 5%.

Avoid overcommitting vCPUs on heavily loaded hosts.

Monitor Prism Central Runway Metrics to predict future CPU resource needs.

Nutanix AHV CPU Scheduling Optimization:

Ensure proper VM sizing (avoid excessive vCPU allocation).

Balance workloads using Nutanix AHV DRS.

Capacity Runway analytics in Prism Central rely on historical usage data to generate forward-looking projections. Nutanix documentation specifies:

“Capacity runway forecasts require a minimum of 30 days of historical utilization data to build growth rate baselines and trending models.”

The modeling engine uses CPU, memory, and storage trends over time to estimate depletion dates. Insufficient historical data prevents generating meaningful predictions.

Prism Central will display “Not enough data” or simply omit runway metrics until the minimum time window is met.

The 21-day threshold applies to anomaly detection, not runway calculations.

The 3-month and 6-month options refer to optimal historical windows for accuracy but are not required.

Thus, the correct requirement is 30 days of history.

Nutanix Prism Central uses Role-Based Access Control (RBAC) combined with Projects to segment access to workloads. Documentation describes Projects as:

“Projects provide a scalable method to group VMs and assign user or group permissions so that access is restricted to only the resources belonging to that project.”

When VMs are added to a project, Prism Central automatically handles:

scoping of administrative permissions

allowed actions (power, console, modify)

limiting visibility only to VMs inside that project

isolation between different teams or business units

Role mapping alone does not limit scope; it only assigns permissions. Without projects, users may see more VMs than intended. VPCs relate to Flow Virtual Networking and network segmentation, not Prism RBAC or VM-level access control. Security Policies isolate network traffic, not administrative visibility.

Thus, creating a project for each team lead and assigning VM access is the most efficient and intended Nutanix mechanism.

A single vCPU is likely causing a bottleneck, limiting the VM’s ability to process I/O requests efficiently.

Option D (Increase the VM’s number of vCPUs) is correct:

Windowsrequires sufficient CPU resourcesto handle disk and network operations.

Adding more vCPUs allows the VM to process more I/O operations simultaneously, improving performance.

Option A is incorrect:

AdditionalvSCSI controllers are only useful for very high disk I/O workloads.

Option B is incorrect:

Balance-TCP applies to network traffic, not storage performance.

Option C is incorrect:

CVM resources do not directly affect individual VM performance.