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

A. Ignoring NetApp Active IQ health risks

Explanation:NetApp Active IQ provides proactive monitoring and alerts for system health risks, including risks related to WAFL inconsistencies. Ignoring these alerts can lead to unresolved issues such as metadata corruption, hardware failures, or system misconfigurations, increasing the chances of WAFL inconsistencies.

Examples of Active IQ Risks:

Disk health warnings.

High write latency or metadata bottlenecks.

Aggregates running out of space.

C. Using outdated disk firmware

Explanation:Outdated disk firmware can cause performance issues, drive failures, or incorrect handling of I/O operations, potentially leading to WAFL inconsistencies. Disk firmware updates often include fixes for critical issues that improve reliability and prevent data corruption.

Importance:Keeping firmware updated ensures compatibility with ONTAP and minimizes risks of disk-level errors that can propagate to WAFL.

Why the Other Options Are Incorrect:

B. Constantly running at high load:

Running at high load can impact performance but does not directly cause WAFL inconsistencies. WAFL is designed to handle high I/O loads efficiently.

D. Upgrading frequently:

Frequent upgrades, when performed correctly, do not increase the chances of WAFL inconsistencies. However, improperly executed upgrades or skipping recommended steps might introduce risks.

References:

NetApp Knowledge Base: Articles on Active IQ health checks and disk firmware management.

ONTAP System Administration Guide: Recommendations for preventing WAFL inconsistencies.

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:

 Best Practices for SAS Cabling in AFF A700 Systems:

The AFF A700 system has built-in SAS ports (e.g., 2a and 2b) as well as additional SAS ports on optional SAS cards.

To ensure high availability and redundancy, it is recommended to distribute SAS connections across multiple SAS ports from different controllers or slots.

 Why Port 2a and 9a Are Recommended:

Port 2a is a built-in SAS port on the AFF A700 system.

Port 9a belongs to the additional SAS card in slot 9.

By connecting the stack using 2a and 9a, you utilize different SAS domains (built-in controller ports and add-on card ports), providing both path redundancy and load balancing.

 NetApp Reference Documentation:

"NetApp Hardware Universe" and "ONTAP Hardware Installation Guide" highlight that SAS cabling for redundancy should leverage different ports, including those from separate SAS controllers or add-on cards.

NetApp's best practice guidelines suggest avoiding connections to the same SAS controller or port group for critical stacks.

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:

 Command Syntax for Downloading ONTAP Image:

The cluster image package get command is used to download the ONTAP image from a specified URL to the cluster's image repository.

The syntax requires the –url parameter followed by the full URL of the image file.

 Why Option C Is Correct:

This command syntax directly downloads the image from the local web server at to the ONTAP cluster repository.

Other options either refer to incorrect commands or unsupported URLs.

 NetApp Reference Documentation:

The "ONTAP Software Upgrade Guide" provides the exact command and steps for downloading ONTAP images via HTTP or FTP.

If a node is not booting, the following methods can be used to access the system for troubleshooting:

What it does:The SP provides out-of-band management access to the node, even if the node is not booting.

How to use:

Connect to the SP using SSH or a direct console connection.

Use SP commands to gather logs or perform diagnostics.

1. Service Processor (SP)

What it does:The serial console provides direct access to the node's bootloader or maintenance mode.

How to use:

Connect to the serial port using a terminal emulator.

Use console commands to interact with the system.

2. Serial Console

A. node management port:

The node management interface is only accessible if the node is booted and ONTAP is running.

B. cluster management port:

The cluster management interface requires the cluster to be operational, which is not possible if the node is not booting.

Why Other Options Are Incorrect:

NetApp "Service Processor and Serial Console Guide" provides instructions for accessing a non-booting node.

References:

To collect shelf logs for a DS4246 shelf in an ONTAP 9.12.1 system, you must invoke a diagnostic AutoSupport specifically targeting the storage subsystem. This action ensures that detailed storage logs, including shelf logs, are included in the AutoSupport bundle.

Use the following command:

Steps to Collect Shelf Logs:bash

Copy code

system node autosupport invoke -node -type diagnostic -subsystem storage

Replace with the name of the node experiencing the issue.

This command generates an AutoSupport message that includes logs related to storage subsystems, such as disk shelves and adapters.

Provide the AutoSupport case number to NetApp Support for further analysis.

A. Provide the output of the nodeshell command rdfile /etc/log/shelflog:

While this command allows manual reading of shelf logs, it is not a recommended or comprehensive approach for collecting logs for NetApp Support cases.

B. Invoke an AutoSupport of type all using Active IQ Unified Manager:

This action generates a generic AutoSupport bundle, which may not include detailed shelf logs unless explicitly targeted.

D. Invoke a diagnostic AutoSupport with the subsystem log_files:

The log_files subsystem targets general system logs, not storage-specific logs like shelf logs.

Why Other Options Are Incorrect:

"ONTAP 9 AutoSupport and Diagnostics Guide" outlines the use of the subsystem storage option for collecting shelf logs.

The "Troubleshooting Storage Subsystems" documentation specifies diagnostic AutoSupport as the method for gathering shelf-related logs.

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.

When ONTAP detects a WAFL inconsistency in an aggregate, it automatically generates an AutoSupport message with the description WAFL INCONSISTENT BLOCK.

WAFL INCONSISTENT BLOCK:

This error indicates that WAFL metadata or user data blocks have been found to be inconsistent.

ONTAP triggers an automatic AutoSupport message to notify administrators and NetApp Support.

Key Details:

A. MEDIUM ERROR DURING RECONSTRUCTION:

This error occurs during disk reconstruction, not due to WAFL inconsistencies.

B. CHECKSUM ERROR:

A checksum error indicates a disk-level data integrity issue, not a WAFL inconsistency.

C. WAFL INCONSISTENT USER DATA BLOCK:

While related, this is not the specific AutoSupport message triggered by ONTAP.

Why Other Options Are Incorrect:

NetApp "ONTAP WAFL Troubleshooting Guide" describes AutoSupport messages related to WAFL inconsistencies.

References:

In a SAS stack of shelves, the connection between the expander and the disk uses a point-to-point topology.

Point-to-Point:

Each SAS disk in a shelf connects directly to the expander using a dedicated channel. This ensures that communication between the disk and expander is independent of other disks, improving performance and reliability.

Why SAS Uses Point-to-Point:

SAS (Serial Attached SCSI) eliminates the shared bandwidth limitations of traditional bus architectures (e.g., arbitrated loop or ring) by dedicating a connection to each device.

Key Details:

A. arbitrated loop:

Arbitrated loop is a topology used in Fibre Channel systems, not SAS.

C. loop:

SAS does not use loop-based communication; this is typical of older technologies like SCSI Parallel Interface (SPI).

D. ring:

Ring topology is not used in SAS stacks.

Why Other Options Are Incorrect:

"NetApp SAS Shelf and Disk Configuration Guide" specifies point-to-point communication between expanders and disks in SAS environments.

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:

 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 analyze the provided panic error, the two sections of AutoSupport that are essential for investigation are:

What it is:HA-RASTRACE.TGZ contains HA (High Availability) system trace logs. It records hardware diagnostics, error traces, and the HA system's response to hardware events. These logs are critical when analyzing hardware-related panics, including those caused by PCI errors.

Why it's relevant to the panic:In the given panic message, the NMI (Non-Maskable Interrupt) error originates from a Qlogic FC 16G adapter. HA-RASTRACE.TGZ will provide detailed diagnostics, including the error reporting from the HA interconnect and other hardware diagnostics. Specifically, it may include information about how the system detected the PCI fault and any actions taken to protect the system state.

How to analyze:

Extract the HA-RASTRACE.TGZ file from the AutoSupport bundle.

Review hardware-related trace messages for entries associated with the PCI bus or the Qlogic FC adapter.

Look for specific error codes or keywords like PCI Error, NMI, or Qlogic.

References:

NetApp’s "AutoSupport Logs and Diagnostics Guide" highlights HA-RASTRACE.TGZ as a primary resource for debugging hardware faults.

The "Panic Troubleshooting Guide" for ONTAP systems specifies HA-RASTRACE as a key source for identifying NMI-related errors.

1. HA-RASTRACE.TGZ

What it is:SSRAM-LOG records low-level hardware error details, including PCI device register states and uncorrectable memory errors. It is particularly useful for analyzing errors originating in peripheral hardware like network or storage adapters connected via PCI.

Why it's relevant to the panic:The panic message explicitly references a PCI Error NMI caused by a Qlogic FC adapter. SSRAM-LOG captures detailed state information for PCI devices, which can help identify whether the fault originated in the adapter hardware, the PCI bus, or another related component.

How to analyze:

Extract the SSRAM-LOG from the AutoSupport bundle.

Search for PCI-related errors, including the specific error source IDs (e.g., ErrSrcID(CorrSrc(0xf00),UCorrSrc(0x18))).

Review the log entries to confirm the root cause of the NMI.

References:

The "Hardware Diagnostics and Troubleshooting Guide for ONTAP" lists SSRAM-LOG as a key file for debugging PCI errors.

NetApp’s documentation on PCI diagnostics emphasizes the use of SSRAM-LOG for validating hardware-level faults.

2. SSRAM-LOG

 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.

A. NVMEM battery

Explanation:The NVMEM (Non-Volatile Memory) battery is a critical component for retaining data in case of a power failure. It is classified as a Field Replaceable Unit (FRU) in an AFF A220 system.

Replacement Notes:

Replacement can be performed by field engineers.

The system will typically alert you when the battery requires replacement.

B. mSATA boot device

Explanation:The mSATA (mini-SATA) boot device contains the ONTAP operating system and is also a FRU in the AFF A220. It is critical for the system's boot process and can be replaced if it becomes faulty.

Replacement Notes:

Boot devices are easily replaceable while ensuring ONTAP is reinstalled on the new device.

Why the Other Options Are Incorrect:

C. NVMe Flash Cache feature:

Incorrect. NVMe Flash Cache is not a physical FRU but a feature for accelerating read performance. It is implemented via software and NVMe-based SSDs, which are not specifically field replaceable in AFF A220.

D. Chassis fan:

Incorrect. The AFF A220 does not classify chassis fans as FRUs. These are usually part of the cooling system, but their replacement may require system shutdown or is integrated into the design.

References:

NetApp Hardware Documentation: AFF A220 Component Replacement Guide.

NetApp Knowledge Base: Articles on replacing NVMEM batteries and mSATA boot devices.

On a FAS9000 system running ONTAP 9.12.1, the kernel core file is stored on the root aggregate. This is the default location where ONTAP writes kernel core files for system-level failures.

The root aggregate is the aggregate that contains the root volume for a given node in the cluster. This aggregate is used for critical system files and logs, including kernel core files.

When a kernel panic or other critical failure occurs, the core dump is written to the root aggregate for later analysis by NetApp Support.

Key Details:

A. on the partner root aggregate: The partner root aggregate is not used for storing core files unless explicitly configured (which is not the default behavior).

C. on the mailbox disk: The mailbox disk is used for cluster quorum and configuration information, not for storing core files.

D. on the boot device: The boot device contains ONTAP software and boot files but does not store kernel core dumps.

"ONTAP System Administration Guide" specifies that core files are stored on the root aggregate.

NetApp’s "Troubleshooting and Diagnostics Guide" confirms the default behavior for kernel core file storage.

Why Other Options Are Incorrect:References:

When a node panics in ONTAP, a kernel core file is generated. This core file contains information about the kernel's state at the time of the panic and is essential for debugging system crashes.

A kernel core file is produced during a node panic to capture information about the kernel, memory, and processes that led to the crash.

The core file is stored on the root aggregate by default and can be uploaded to NetApp Support using the autosupport invoke-core-upload command.

Key Details:

A. mgwd core:

This is related to the Management Gateway daemon, which handles management traffic. It does not generate a core file during a panic.

B. user space core:

User space cores are generated for processes running in user space, not for kernel panics.

C. sync core:

Sync cores refer to synchronized cores for debugging but are not the primary type generated during a node panic.

Why Other Options Are Incorrect:

"ONTAP Panic Troubleshooting Guide" specifies kernel core files as the output of a node panic.

"ONTAP Core File Management Guide" details the handling of kernel core files after a crash.

References:

To diagnose a PCI/NMI error and collect logs, use the following commands:

What it does:This command collects PCI error logs, including detailed information about PCI devices and the errors that caused the panic.

How to use:Run the command from the nodeshell to capture the required PCI log entries.

1. pelog –a –g=2

What it does:This command reads the SSRAM log file, which contains low-level error information related to PCI and other hardware subsystems.

How to use:Run the command to view the log entries directly for detailed troubleshooting.

2. rdfile /mroot/etc/log/SSRAM

B. show pci –v:

While this command displays PCI device information, it does not provide detailed error logs.

D. event log show:

This displays event log entries but does not contain the specific PCI or NMI-related logs required for diagnosing the panic.

Why Other Options Are Incorrect:

"ONTAP Hardware Troubleshooting Guide" lists pelog and SSRAM as tools for analyzing PCI errors.

"ONTAP Panic Analysis Guide" emphasizes the importance of collecting detailed hardware logs.

References: