Netapp NS0-093 NetApp Accredited Hardware Support Engineer Exam Practice Test

Description:

When a negotiated takeover occurs (e.g., for maintenance or upgrades), NVRAM data is replayed by the HA partner to ensure no data is lost.

Relevance:

This ensures that all pending writes are safely processed by the partner node.

1. During a Negotiated Takeover:

Description:

If a node loses power unexpectedly, the HA partner replays the mirrored NVRAM data to protect active write operations.

2. When the Node Loses Power:

A. after triggering a sync core:

Triggering a sync core does not involve NVRAM replay; it captures the system state for debugging.

B. when a node is halted:

Halting a node does not trigger NVRAM replay unless it is part of a negotiated takeover.

Why Other Options Are Incorrect:

"ONTAP High Availability Guide" explains NVRAM mirroring and replay during failover scenarios.

References:

 FRUs on FAS9000 Supporting Replacement Without Takeover:

A (I/O Module): I/O modules can be replaced hot (without takeover) to maintain system uptime during hardware servicing.

D (NVRAM Module): NVRAM modules on FAS9000 can also be replaced without a node takeover, ensuring data integrity during replacement.

 Why Other Options Are Incorrect:

B (DCPM Module): The DCPM (Data Center Power Management) module is not hot-swappable and requires a node takeover.

C (Caching Module): The caching module is integrated and typically requires a node takeover or power-down for replacement.

 NetApp Reference Documentation:

Refer to the "NetApp FAS9000 Hardware Service Guide" for supported FRU replacement procedures and operational constraints.

To view information about installed Field Replaceable Units (FRUs) using the Service Processor, the following commands are used:

What it does:Displays a list of all installed FRUs, such as disks, power supplies, and fans.

Example Usage:

1. system fru listsystem fru list

What it does:Provides detailed information about specific FRUs, including serial numbers, statuses, and hardware details.

2. system fru showsystem fru show

C. system sensors show:

This command displays sensor data (e.g., temperature, voltage) but does not list FRUs.

D. system power status:

This command shows power supply status but does not provide FRU details.

Why Other Options Are Incorrect:

"Service Processor Commands Guide" from NetApp provides a comprehensive overview of system fru list and system fru show.

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.

 Functionality of RAID Error Propagation (REP):

RAID Error Propagation (REP) ensures that errors on the disk layer, such as unrecoverable read errors, do not propagate as inconsistencies into the WAFL (Write Anywhere File Layout) metadata layer.

WAFL is designed to manage data blocks, and if an error occurs on a user data block, WAFL can identify and handle it gracefully without flagging an inconsistency.

 Why Option A Is Correct:

REP ensures that errors on a user data block are isolated and do not trigger WAFL inconsistencies. Instead, the error is handled at the RAID layer or higher without corrupting metadata.

This design provides a robust mechanism to protect against data integrity issues caused by disk errors.

 NetApp Reference Documentation:

Refer to the "ONTAP Storage Management Guide" and the "NetApp RAID Guide," which explain how RAID and WAFL interoperate and how REP is implemented.

 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.

To trigger an AutoSupport message in ONTAP, the following commands are valid:

What it does:This command manually triggers a complete AutoSupport message of type "all." This includes logs and system information from all subsystems.

How to use:

Run the command: autosupport invoke –node –type all

Replace with the name of the node for which you want to generate the AutoSupport message.

Why it's relevant:This is the primary method for triggering a full AutoSupport message manually. It is commonly used during troubleshooting to provide comprehensive system data to NetApp Support.

1. ::> autosupport invoke –node –type all

What it does:This command is specifically used to upload core files (e.g., kernel or user space cores) from a node to NetApp Support for analysis.

How to use:

Run the command: autosupport invoke-core-upload –node .

Replace with the name of the node for which you want to upload core files.

Why it's relevant:If there is a system panic or other critical issue, this command ensures that core files are included in the AutoSupport message for detailed analysis.

2. ::> autosupport invoke-core-upload –node

A. ::> autosupport history show-upload-details –node <nodename>:

This command displays the history of AutoSupport uploads but does not trigger a new AutoSupport.

B. ::> system node coredump upload –node <nodename>:

This command uploads coredumps directly to a support server but does not trigger an AutoSupport message.

Why Other Options Are Incorrect:

"ONTAP 9 AutoSupport Configuration Guide" confirms autosupport invoke as a valid command to trigger AutoSupport messages.

"ONTAP CLI Reference Manual" specifies autosupport invoke-core-upload for core file uploads.

References:

To replace a drawer in a DS460c shelf, the following steps must be taken:

Why this is required:Cable chains connect the drawer to the shelf and must be disconnected to safely remove the drawer.

1. Disconnect the cable chains from the chassis

Why this is required:Drives must be removed to avoid damage during the drawer replacement process and to reduce the weight of the drawer for safe handling.

2. Evacuate all drives in the drawer

A. Shut down both nodes:

This is unnecessary because DS460c shelves support online replacement, and the system can remain operational.

C. Power off the shelf:

This is also unnecessary. DS460c shelves are hot-swappable, meaning they do not require the shelf to be powered down.

Why Other Options Are Incorrect:

"DS460c Hardware Service Guide" explains the procedure for replacing a drawer.

NetApp’s "Field Replacement Guide" for DS460c shelves emphasizes online and hot-swappable replacements.

References:

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:

When a WAFL inconsistency is detected, the first step is to stabilize the system before attempting any repairs or recovery.

Stabilize the System:

Ensure that the system is not experiencing ongoing hardware or software issues.

Avoid making changes to the affected aggregate or volume until the system is stable.

Assess the Impact:

Determine which aggregates or volumes are affected and the severity of the inconsistency.

Steps to Handle WAFL Inconsistency:

A. Run wafliron:

Running wafliron should only be done after stabilizing the system and under guidance from NetApp Support.

C. Force offline the affected aggregate:

Forcing an aggregate offline without proper assessment can lead to data loss.

D. Run a dump to null:

Dumping data is not relevant for resolving a WAFL inconsistency.

Why Other Options Are Incorrect:

"NetApp WAFL Troubleshooting Guide" specifies that stabilization is the first step after detecting inconsistencies.

NetApp Support documentation provides guidelines for handling WAFL inconsistencies safely.

References:

In maintenance mode, the command disk show –v provides detailed information about disk ownership. This includes the current owner, previous owner, and disk health status.

Enter maintenance mode, and run:

How to Use:disk show –v

The output will display ownership information for each disk, including its RAID group and current assignment.

A. sysconfig –v:

This command provides system configuration details but does not show disk ownership.

C. aggr status:

This command shows the status of aggregates, not individual disks or their ownership.

D. storage show disk –p:

This command is not valid in maintenance mode.

Why Other Options Are Incorrect:

NetApp "Maintenance Mode Commands Guide" highlights disk show –v as the command to check disk ownership.

References:

For an automatic takeover to occur in an HA pair, the following conditions must be met:

The HA pair uses mailbox disks to coordinate and ensure that both nodes have consistent cluster state information.

If the mailbox disks are not reachable, the takeover process cannot proceed.

1. Mailbox Disks Must Be Reachable:

The nodes in an HA pair continuously mirror NVRAM data to ensure that writes are protected.

If NVRAM is not synchronized, the takeover cannot safely handle active workloads.

2. NVRAM Must Be Synchronized:

A. The combined utilization of both nodes must be less than 100%:

This is not a requirement for automatic takeover. ONTAP can handle higher utilization during failover scenarios.

B. The cluster network must be available:

While the cluster network is critical for normal operation, takeover can still occur if the cluster network is unavailable, as long as the HA interconnect is operational.

Why Other Options Are Incorrect:

NetApp "ONTAP High Availability Guide" outlines the requirements for automatic takeover in HA pairs.

"ONTAP NVRAM Synchronization and Failover Guide" explains NVRAM mirroring requirements.

References:

 Options for Uploading Core Files:

Core files are diagnostic dumps created during system failures for analysis by NetApp Support.

They can be uploaded via multiple methods, depending on system configuration and access:

 Option B (CIFS Download):

Core files can be downloaded from the node using a CIFS share and then manually uploaded to upload.netapp.com.

This method is useful if automated processes are unavailable or connectivity is limited.

 Option D (Autosupport Invoke-Core-Upload):

The command system node autosupport invoke-core-upload automates the process of uploading the core file to NetApp.

It uses the configured Autosupport mechanism to transfer the file to NetApp Support for analysis.

 NetApp Reference Documentation:

"ONTAP Autosupport Guide" and "ONTAP Troubleshooting Guide" provide instructions for manually and automatically uploading core files.

To troubleshoot the root cause of an unexpected controller reboot, the following tools are commonly used:

What it does:Provides monitoring and performance data for the ONTAP cluster, including historical event logs that may help identify the root cause of a reboot.

1. Active IQ Unified Manager

What it does:The CLI allows you to gather logs and status information directly from the affected node. Commands like event log show and system core are essential for identifying the reason behind the reboot.

2. ONTAP CLI

B. Active IQ Digital Advisor:

This tool focuses on predictive analytics and proactive recommendations, not troubleshooting unexpected reboots.

D. ONTAP Mediator:

This tool is used for managing MetroCluster configurations, not for troubleshooting reboots.

E. Active IQ Config Advisor:

This tool checks for configuration best practices but does not provide detailed logs or reboot diagnostics.

Why Other Options Are Incorrect:

NetApp "ONTAP System Management Guide" emphasizes the use of Unified Manager and CLI for troubleshooting system issues.

References:

 Reverting to a Previous ONTAP Version:

Reverting ONTAP software requires specific procedures and is only supported if the ONTAP version being reverted to is compatible with the current cluster configuration.

 Why the Netboot Procedure Is Used:

The netboot process loads the desired ONTAP version directly into memory from a network location and reinitializes the system.

This method is used when a full software revert is required and is often necessary for downgrades to a version that cannot be directly reverted to from the running ONTAP version.

 Key Notes:

A direct revert is not supported from ONTAP 9.7 to ONTAP 9.5 using standard methods due to system metadata changes.

Always verify compatibility using the "ONTAP Software Version Interoperability Matrix".

 NetApp Reference Documentation:

Refer to the "ONTAP Revert/Downgrade Guide" for specific instructions on using the netboot procedure.

To recover an inconsistent aggregate, the following tools can be used:

What it does:This tool is used to perform a consistency check on WAFL metadata. It identifies and attempts to fix WAFL inconsistencies in aggregates.

When to use:Run wafl_check after identifying WAFL inconsistencies to repair minor metadata issues.

1. wafl_check

What it does:This tool repairs WAFL inconsistencies by reconstructing metadata. It is more powerful than wafl_check and should only be run under NetApp Support guidance, as improper use can result in data loss.

When to use:Use wafliron for severe WAFL inconsistencies that cannot be resolved by wafl_check.

2. wafliron

A. file check:

This is not a valid NetApp tool.

C. wafl snapiron:

While similar in name, snapiron is used for snapshot recovery, not aggregate recovery.

Why Other Options Are Incorrect:

"ONTAP Aggregate Troubleshooting Guide" details the usage of wafl_check and wafliron.

NetApp Support documentation provides guidelines for recovering inconsistent aggregates.

References:

If the root volume runs out of space, it can cause operational issues and require recovery.

The root volume must always have sufficient space for system logs, configuration files, and core dumps.

1. Root Volume Ran Out of Space:

When a mainboard is replaced, the system configuration stored in the root volume may need to be restored or recovered.

2. Mainboard Was Replaced Following an NMI Panic:

C. Root volume migrate was performed:

Root volume migration is a normal operation and does not typically cause the need for root volume recovery.

D. The cluster configuration is out of sync on the volume:

While this can cause configuration issues, it does not directly lead to root volume recovery.

Why Other Options Are Incorrect:

"ONTAP Root Volume Management Guide" explains scenarios leading to root volume issues and recovery procedures.

References:

Reverting to a previous ONTAP version requires careful preparation because ONTAP upgrades often introduce irreversible changes. To successfully revert, the following actions are needed:

C. Reinstall your boot media and install ONTAP 9.5 software

Explanation:You need to reinstall the older version of ONTAP (9.5) on the boot media because the current version (9.7) has been installed as part of the upgrade. The reinstallation ensures that the system boots with ONTAP 9.5.

Steps:

Boot the node into maintenance mode.

Perform the reinstallation using the appropriate ONTAP 9.5 image.

D. Wipe your config and restore from backup

Explanation:A revert requires wiping the configuration because ONTAP upgrades may have made changes to the cluster configuration or WAFL metadata. Restoring the configuration from a backup ensures consistency with the older ONTAP version.

Steps:

Back up the current cluster configuration before proceeding.

Use the restored backup after the revert is complete to reconfigure the system.

Why the Other Options Are Incorrect:

A. Revert from ONTAP 9.7 software to ONTAP 9.6 software and then to ONTAP 9.5 software:

Incorrect. ONTAP reverts must directly target the desired version. You cannot perform multi-step reverts.

B. Delete all Snapshot copies from the past two days:

Incorrect. Deleting Snapshot copies is not a prerequisite for reverting ONTAP. While older Snapshot copies might not be compatible with the reverted version, they do not need to be deleted before the revert.

References:

NetApp Documentation: ONTAP Upgrade and Revert Procedures.

NetApp Knowledge Base: Steps for reinstallation and configuration restoration during a revert.