NS0-093 Exam Dumps - Netapp NAHSE Questions and Answers

 Possible Causes for "No Disks" Error:

A (Incorrect SAS Cabling): If the SAS cables are incorrectly reconnected or swapped after replacing the boot device, the disks may not be detected because the physical connection to the shelves is compromised. Verifying and reseating the SAS cables is essential.

C (Lower ONTAP Version): If the node boots into an ONTAP version that is lower than the version previously used, it might not recognize the RAID labels or disk metadata created by the higher ONTAP version.

 Why Other Options Are Incorrect:

B (Disks Marked as Failed): Disks that are marked as failed would still be visible in the system, though unusable.

D (Interconnect Down): An interconnect failure affects HA functionality but does not prevent a node from detecting its own disks.

 NetApp Reference Documentation:

Refer to the "ONTAP Boot Recovery Guide" and "SAS Cabling Guide" for steps to resolve disk detection issu

When a node fails to boot and loads the previous version of ONTAP, it usually indicates that the primary boot location is incorrect. To resolve this:

Enter the LOADER Prompt:

Interrupt the boot process to access the LOADER prompt.

Set the Primary Kernel URL:

Use the following command:

Steps to Boot the Correct ONTAP Version:setenv GX_PRIMARY_KERNEL_URL

Boot the Node:

Run the boot command to load the correct version.

B. From the loader prompt of nodeA1, run boot_backup:

Booting the backup image may result in an outdated version of ONTAP, not the desired version.

C. From the clustershell of the partner, run system node image modify:

Modifications to the ONTAP image must be done from the LOADER prompt, not the clustershell.

D. From the clustershell of nodeA1, run system node image modify:

NodeA1 cannot load ONTAP, so this command cannot be run.

Why Other Options Are Incorrect:

"ONTAP System Boot Guide" explains how to resolve boot issues using the LOADER prompt.

NetApp documentation on environment variables includes the use of GX_PRIMARY_KERNEL_URL.

References:

 Steps to Unfail a Disk in Maintenance Mode:

When a disk is marked as "failed," it is added to the Failed Disk Registry and marked as unusable by the system. Unfailing a disk involves removing it from this registry and resetting its state.

 Step 1: Remove the Disk from the Failed Disk Registry

Use the command: registry remove to delete the disk from the Failed Disk Registry. This clears its "failed" status.

 Step 2: Use the Disk Unfail Command

Execute the disk unfail command to reset the disk status and make it available for use.

 Key Notes:

After unfailing, the disk will be treated as a spare and must be reassigned or re-added to an aggregate.

If the disk remains failed after these steps, physical hardware issues may need to be addressed.

 NetApp Reference Documentation:

The "ONTAP Maintenance Mode Guide" and "Disk Management Guide" provide detailed instructions for handling failed disks and using the disk unfail command.

Description:

L1 WDR is a hardware-initiated reset that occurs when the system detects an unrecoverable error or lockup lasting 0.5 seconds.

Key Characteristics:

It performs a hard reset, meaning the system immediately reboots without creating a core dump.

1. L1 Watchdog Reset (WDR):

Description:

L2 WDR is initiated when the system fails to recover from a critical fault after 2 seconds.

Key Characteristics:

It requests a core dump to capture the system state for diagnostic purposes before performing a reset.

2. L2 Watchdog Reset (WDR):

B. L1 WDR is initiated after 0.5 seconds from the event:

This is incorrect because L1 WDR performs a hard reset and does not initiate after 2 seconds.

C. L1 WDR performs a soft reset:

This is incorrect because L1 WDR performs a hard reset, not a soft reset.

Why Other Options Are Incorrect:

"ONTAP Panic Analysis Guide" describes the behavior and timing of L1 and L2 WDR events.

NetApp Support documentation on system resets explains the differences between L1 and L2 watchdog resets.

References:

If the ENVIRONMENT section of the latest MANAGEMENT LOG AutoSupport message is empty, the reason can typically be found in the AUTOSUPPORT-BUDGET.XML file. This file contains information about AutoSupport resource allocation, including what sections were processed and any limits that were hit.

AUTOSUPPORT-BUDGET.XML:

This file provides a summary of the resources (budget) allocated for different AutoSupport sections.

If the ENVIRONMENT section is missing or empty, the AUTOSUPPORT-BUDGET.XML file will indicate whether it was skipped due to resource constraints or configuration limits.

Why Other Sections Do Not Apply:

B. HEADERS: This section only contains metadata about the AutoSupport message, such as timestamps and node details. It does not explain missing sections.

C. AUTOSUPPORT-HISTORY.XML: This file tracks the history of AutoSupport messages but does not provide information about missing sections.

D. MANIFEST.XML: This file lists the contents of the AutoSupport bundle but does not provide details on why a specific section is empty.

Key Details:

"ONTAP AutoSupport Troubleshooting Guide" explains the role of the AUTOSUPPORT-BUDGET.XML file in diagnosing missing or incomplete AutoSupport sections.

References:

 Purpose of the -cfo-only true Option:

This option is used during the giveback process in a NetApp cluster to control which aggregates are returned to the original node.

By specifying -cfo-only true, only the data aggregates are given back to the original node, while the root aggregate remains with the takeover node.

 Use Case:

This command is helpful when you want to test the aggregate giveback functionality or if the root aggregate requires further investigation or maintenance before returning it to the original node.

 NetApp Reference Documentation:

The "ONTAP High-Availability Configuration Guide" and "Cluster Failover Management Guide" detail the behavior of the -cfo-only option during giveback scenarios.

 Overview of IOM 12 Module:

The IOM 12 module is used in NetApp storage shelves for SAS connectivity.

 Key Features of IOM 12:

SAS Ports: The IOM 12 module has four SAS ports (two IN and two OUT) to support daisy-chaining of shelves and provide redundancy.

ACP (Alternate Control Path): The IOM 12 includes an Ethernet port for ACP, which is used for out-of-band management and monitoring of the storage shelves.

 Elimination of Other Options:

Option A is incorrect because the module has four SAS ports, not two.

Option C is incorrect because the module does include an Ethernet port for ACP.

 NetApp Reference Documentation:

"NetApp Hardware Universe" lists the specifications of the IOM 12 module, including its SAS and ACP capabilities.

The "ONTAP Shelf Installation Guide" discusses ACP and its role in shelf management.

To determine whether an aggregate is WAFL (Write Anywhere File Layout) inconsistent, the following two commands can be used:

What it does:This command directly checks the WAFL consistency status of the specified aggregate. If an aggregate is WAFL inconsistent, it will report the inconsistency in the output.

How to use:

Run the command: wafiron show (replace with the name of the aggregate).

Look for indications of WAFL inconsistency in the output.

Why it's relevant:The wafiron utility is specifically designed to provide WAFL status and diagnostics. It is the most accurate and direct way to confirm whether an aggregate is inconsistent.

References:

"WAFL Troubleshooting Guide" from NetApp highlights the wafiron show command as a primary tool for checking aggregate consistency.

1. wafiron show

What it does:This command displays RAID information for all aggregates on the specified node. If an aggregate is WAFL inconsistent, it will be explicitly mentioned in the output.

How to use:

Run the command: node run –node sysconfig –r.

Check the output for the phrase "WAFL inconsistent" under the corresponding aggregate.

Why it's relevant:This command provides additional context, such as the RAID group details, which can help understand whether the inconsistency is isolated or part of a larger issue.

References:

"ONTAP CLI Commands Guide" specifies sysconfig –r as a method to verify aggregate status, including WAFL consistency.

2. node run –node sysconfig –r

C. storage aggregate show:

This command displays aggregate configuration and usage information but does not report WAFL inconsistency.

D. node run –node <node> sysconfig –a:

While this command shows detailed hardware configuration information, it does not include WAFL consistency status for aggregates.

Why Other Options Are Incorrect:

When an aggregate fails due to multiple disk failures caused by a faulty I/O module (IOM), the first step after replacing the faulty IOM is to manually unfail the affected drives. This process is done in maintenance mode.

Enter Maintenance Mode:

Reboot the node and interrupt the boot process to access maintenance mode.

Identify Failed Drives:

Use the command:

Steps to Recover the Aggregate:sql

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storage show disk –broken

This command lists all failed (broken) drives.

Unfail the Drives:

Use the following command for each failed drive:

php

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disk unfail

Reconstruct the Aggregate:

Once all drives are unfail, the system should begin reconstructing the RAID groups in the aggregate.

A. Use diskcopy from maintenance mode:

Diskcopy is used for cloning or copying data between disks, not for recovering failed aggregates.

B. Run wafliron from the boot_menu:

wafliron is used to repair WAFL inconsistencies, but it does not help recover failed aggregates due to disk issues.

D. Unfail the drives in the order that they failed from the clustershell:

Drives must be unfail in maintenance mode, not from the clustershell.

Why Other Options Are Incorrect:

NetApp’s "Aggregate and RAID Troubleshooting Guide" explains the process of recovering aggregates and using maintenance mode commands.

"ONTAP Disk Recovery Guide" outlines steps to unfail disks and recover RAID groups.

References: