NetApp Accredited Hardware Support Engineer NS0-093 Exam Questions

Answer : A, B

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.

NetApp Hardware Documentation: AFF A220 Component Replacement Guide.

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

Answer : B, C

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 <disk> 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 <disk> 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.

Answer : B

RAID-TEC Overview:

RAID-TEC (Triple Erasure Coding) is a NetApp RAID technology designed to protect against up to three simultaneous disk failures.

It is ideal for systems with high-density disks or workloads requiring extreme fault tolerance.

Why RAID-TEC Is Correct:

RAID-TEC uses triple-parity protection, which provides redundancy against three disk failures, making it more resilient than RAID-DP or RAID 5.

RAID-DP only protects against two disk failures, while RAID 4 and RAID 5 protect against a single failure.

NetApp Reference Documentation:

'NetApp RAID and Data Protection Guide' details the differences between RAID-DP and RAID-TEC, highlighting RAID-TEC's ability to tolerate three failures.

Answer : C

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.

Answer : A

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.

Answer : C, D

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.

NetApp Documentation: ONTAP Upgrade and Revert Procedures.

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

Answer : C

When using wafliron to repair WAFL inconsistencies on an aggregate, the aggregate becomes available after Phase 4 of the wafliron process is complete.

Phases of wafliron:

Phase 1: Initial scan to identify inconsistencies.

Phase 2: Corrects directory and inode structure issues.

Phase 3: Repairs blocks and metadata.

Phase 4: Completes final repairs and verification, after which the aggregate can be made available.

Why Other Options Are Incorrect:

A . when the administrator manually onlines the aggregate:

The aggregate cannot be manually brought online until wafliron completes Phase 4.

B . when wafliron is started:

Starting wafliron does not make the aggregate available; repairs need to be completed first.

D . after the mounting phase of wafliron is complete:

WAFLiron does not have a specific 'mounting phase.' Mounting happens after Phase 4 completes.

'NetApp WAFLiron Troubleshooting Guide' explains the availability of the aggregate after Phase 4.

NetApp Support documentation outlines the phases of wafliron and aggregate recovery.