NCP-US-6.5 Practice Questions

The two steps that the administrator should perform to resolve the connectivity issues with the domain controller servers are:

Verify the DNS settings in Prism Element: DNS (Domain Name System) is a system that translates domain names into IP addresses. DNS settings are configurations that specify which DNS servers to use for resolving domain names. Verifying the DNS settings in Prism Element is a step that the administrator should perform, because it can help identify and correct any incorrect or outdated DNS server addresses or domain names that may cause connectivity issues with the domain controller servers.

Verify the DNS entries for the given domain name: DNS entries are records that map domain names to IP addresses or other information. Verifying the DNS entries for the given domain name is another step that the administrator should perform, because it can help check and update any incorrect or outdated IP addresses or other information that may cause connectivity issues with the domain controller servers. References: Nutanix Files Administration Guide, page 32; Nutanix Files Troubleshooting Guide

The alert A130357 - VolumeGroupProtectionFailedOnPC in a Nutanix environment indicates a failure to protect a Volume Group (VG) in a Protection Domain (PD) managed through Prism Central (PC). Nutanix Volumes, part of Nutanix Unified Storage (NUS), provides block storage via iSCSI, and Volume Groups can be protected using Protection Domains for snapshots and replication. The alert suggests that the protection process failed, likely due to incompatible configurations.

Understanding the Issue:

Volume Group Protection: A Volume Group in Nutanix Volumes can be added to a Protection Domain in Prism Central for data protection (e.g., snapshots, replication).

Protection Failed on PC: The failure occurred during the protection process, managed through Prism Central, indicating an issue with the Protection Domain or policy settings.

Conditions to Address: The failure is likely due to configuration mismatches or unsupported settings in the Protection Domain or policy.

Analysis of Conditions:

Option A (Volume Group is protected in a legacy protection domain): Correct. A “legacy protection domain” refers to an older protection mechanism in Nutanix (e.g., from earlier AOS versions) that may not be fully compatible with newer Prism Central features or Volume Group protection workflows. If the Volume Group is part of a legacy PD, the protection process may fail due to deprecated features or APIs. Addressing this involves migrating the Volume Group to a modern Protection Domain in Prism Central, ensuring compatibility.

Option B (The Protection Policy applied on Volume Group has an Async snapshot schedule applied): Incorrect. An Async (asynchronous) snapshot schedule is a standard and supported configuration for Volume Group protection in a Protection Domain. Async schedules take snapshots at intervals (e.g., hourly, daily) and replicate them to a remote site, and this does not cause protection failures—it’s a valid setup.

Option C (The Protection Policy applied on Volume Group has a NearSync snapshot schedule applied): Correct. NearSync is a near-synchronous replication schedule (e.g., 1-minute RPO, as in Question 24) that is supported for VMs and some Nutanix Files configurations, but it is not supported for Volume Groups in a Protection Domain. If a NearSync schedule is applied to a Volume Group’s Protection Policy, the protection will fail because Volume Groups only support Async schedules. Addressing this involves changing the schedule to an Async policy, which is compatible with Volume Groups.

Option D (Volume Group is not protected in a legacy protection domain): Incorrect. This option suggests that the Volume Group is already in a modern (non-legacy) Protection Domain, which would not cause the failure. The issue lies in specific conditions (e.g., legacy PD or incompatible schedule), so this option does not identify a condition that needs addressing.

Selected Conditions:

A: A legacy Protection Domain can cause compatibility issues, leading to protection failures. Migrating to a modern PD in Prism Central resolves this.

C: A NearSync schedule is not supported for Volume Groups, causing the protection to fail. Switching to an Async schedule ensures compatibility.

Why These Conditions?

Legacy Protection Domain (A): Legacy PDs may use outdated mechanisms that are incompatible with Prism Central’s modern protection workflows for Volume Groups, causing failures.

NearSync Schedule (C): Volume Groups in a Protection Domain only support Async snapshot schedules. A NearSync schedule, designed for low-RPO replication, is not supported and will cause the protection process to fail.

Exact Extract from Nutanix Documentation:

From the Nutanix Prism Alerts Reference Guide (available on the Nutanix Portal):

“Alert A130357 - VolumeGroupProtectionFailedOnPC: This alert is triggered when Volume Group protection fails in a Protection Domain managed through Prism Central. Common causes include:

The Volume Group is protected in a legacy protection domain, which is not fully compatible with modern Prism Central workflows. Migrate the Volume Group to a modern Protection Domain.

The Protection Policy applied to the Volume Group has a NearSync snapshot schedule, which is not supported for Volume Groups. Change the schedule to an Async policy to allow successful protection.”