Free Practice Questions for Netapp NS0-093 Exam

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:

A NetApp WAFL (Write Anywhere File Layout) inconsistency in a RAID-DP aggregate could occur in the following scenarios:

Why this causes inconsistency:

RAID-DP is designed to handle up to two concurrent disk failures. However, if a block error occurs during the reconstruction process (e.g., unreadable data on the surviving disks), the RAID group cannot rebuild the lost data, leading to WAFL inconsistencies.

1. Two disks failing and a block error during reconstruction

Why this causes inconsistency:

If two disks in the same RAID group fail nearly simultaneously (before the RAID-DP can reconstruct data from the first failed disk), the system cannot recover the data, resulting in WAFL inconsistencies.

2. Two disks failing within seconds of each other

B. rebooting a node during a disk reconstruction:

Rebooting a node does not cause WAFL inconsistency because ONTAP ensures that RAID reconstructions resume upon reboot without data loss.

D. both party disks failing:

This is not a valid RAID-DP term.

Why Other Options Are Incorrect:

"WAFL and RAID-DP Operations Guide" explains failure scenarios that could cause inconsistencies.

NetApp's "Troubleshooting RAID Groups and Aggregates" covers recovery procedures for double-disk failures and reconstruction errors.

References:

To confirm the successful completion of an ONTAP upgrade, the cluster image show-update-progress command provides the necessary details.

Command:

Key Command:cluster image show-update-progress

Displays the status of the cluster upgrade, including which nodes have successfully upgraded and whether the process has completed.

A. system controller sp upgrade show:

This command displays information about SP (Service Processor) firmware upgrades, not ONTAP upgrades.

C. job show –jobtype upgrade:

While this command shows upgrade jobs, it does not confirm the completion of the cluster-wide ONTAP upgrade.

D. system node upgrade-revert upgrade-task –node <nodename> –version <ontap Version>:

This command reverts an upgrade task, not confirms completion.

Why Other Options Are Incorrect:

NetApp "ONTAP Upgrade Guide" specifies the cluster image show-update-progress command as the primary method to verify upgrade completion.

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.

 What Is a Watchdog Timeout?

The watchdog is a software or hardware mechanism that monitors the system’s health and ensures it is operating correctly.

If the system fails to respond or update the watchdog timer within the specified time, the watchdog triggers a system panic to avoid further corruption or damage.

 Cause of Watchdog Timeout:

This usually occurs due to:

A hardware failure (e.g., CPU or memory issue).

A software bug causing a system hang or crash.

The panic ensures the system stops operation to preserve data integrity and aid in troubleshooting.

 NetApp Reference Documentation:

"ONTAP Troubleshooting Guide" and "Core Dump Analysis Guide" provide details on interpreting watchdog timeouts and recommended actions.

To manually generate a kernel core file in ONTAP, the following commands can be used:

What it does:Reboots the specified node and generates a core dump before rebooting.

Example Usage:

1. ::> reboot –node –dump truereboot –node –dump true

What it does:Halts the specified node and generates a core dump before shutting down.

Example Usage:

2. ::> halt –dump true –node halt –dump true –node

What it does:Forces a panic on the specified node, which triggers a kernel core dump.

Example Usage:

3. ::> system node panic –node system node panic –node

A. SP> system power cycle:

This command reboots the system from the Service Processor but does not generate a core dump.

E. SP> system core:

This command displays core file information but does not generate a new core dump.

Why Other Options Are Incorrect:

NetApp "Kernel Core Dump Guide" explains the use of reboot, halt, and panic commands to trigger core dumps.

ONTAP CLI Reference includes the syntax for these commands.

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 http://192.168.10.10/ 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.

 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.