NS0-093: NetApp Accredited Hardware Support Engineer

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.

When replacing a boot device on a FAS8300 system and using a USB memory stick for recovery or installation, the external USB port must be explicitly enabled. This is done through the setenv command in the boot environment.

Steps to Enable the External USB Port:

Reboot the system and interrupt the boot process to access the bootloader prompt.

At the bootloader prompt, use the following command:

arduino

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setenv usbport_enabled true

Save the configuration and proceed with the boot process.

Why Other Options Are Incorrect:

B . You need to use ONTAP 9.11 or later software:

ONTAP 9.10P6 fully supports external USB recovery. There is no need to upgrade to ONTAP 9.11 for this functionality.

C . Add the boot device before the BIOS is loaded:

While the USB device must be inserted during the boot process, this alone will not enable access unless the port is enabled via setenv.

D . The external USB port is not activated on NetApp systems:

This is incorrect. The external USB port is supported but must be explicitly enabled in the bootloader environment.

NetApp Hardware Installation Guide for FAS8300 systems outlines the steps for enabling the USB port during recovery.

'ONTAP Boot Troubleshooting Guide' specifies the use of the setenv command to activate USB ports.

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

1. pelog --a --g=2

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.

2. rdfile /mroot/etc/log/SSRAM

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.

Why Other Options Are Incorrect:

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.

'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.

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

1. Two disks failing and a block error during reconstruction

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.

2. Two disks failing within seconds of each other

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.

Why Other Options Are Incorrect:

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.

'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.

The Upgrade Advisor is a NetApp tool that generates a detailed, step-by-step plan for upgrading an ONTAP system. This tool is available through the Active IQ portal and helps ensure a smooth and risk-free upgrade process.

Key Features of Upgrade Advisor:

Provides a tailored upgrade plan based on the current ONTAP version, cluster configuration, and desired target version.

Identifies potential risks, compatibility issues, and pre-requisite tasks for the upgrade.

Offers detailed instructions for each stage of the upgrade process.

Why Other Options Are Incorrect:

A . ONTAP System Manager:

While System Manager can be used to initiate upgrades, it does not generate a detailed upgrade plan.

B . Active IQ Unified Manager:

Unified Manager focuses on monitoring and management but does not provide upgrade plans.

D . Active IQ Config Advisor:

Config Advisor checks for best practices and configuration issues but is not used for generating upgrade plans.

NetApp's 'ONTAP Upgrade Guide' emphasizes the use of Upgrade Advisor for planning upgrades.

Active IQ documentation provides detailed instructions on accessing and using the Upgrade Advisor tool.

The identifier 1.2.3.L1 follows the NetApp disk naming convention, which specifies the location of the drive in the system. Here is the breakdown of the identifier:

1: This indicates the stack ID or loop ID. It represents the stack number in the disk shelf configuration.

2: This indicates the shelf ID. In this case, the drive is located in shelf 2.

3: This indicates the bay ID or slot number within the shelf. The drive is in bay 3.

L1: This represents the logical port or logical disk identifier.

How to Interpret Disk Identifier 1.2.3.L1:

The shelf ID is 2, so the drive is in shelf 2 (A is correct).

The bay ID is 3, so the drive is in bay 3 (B is correct).

Why Other Options Are Incorrect:

C . The drive is in bay 2: The bay ID is explicitly specified as 3, not 2.

D . The drive is in shelf 1: The shelf ID is clearly given as 2, not 1.

NetApp Hardware Universe documentation provides details on disk naming conventions.

The 'ONTAP Disk Management Guide' includes a full explanation of disk IDs and their interpretation.

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 invoke AutoSupport in ONTAP, the following tools can be used:

1. CLI (Command Line Interface)

How to use: Run the command:

python

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autosupport invoke -node <nodename> -type all

This triggers AutoSupport to collect and send logs and system information.

2. NetApp Active IQ website

How to use: Log in to the Active IQ portal and use its interface to request an AutoSupport message from the connected ONTAP systems.

Why Other Options Are Incorrect:

A . NetApp Cloud Insights:

This tool is used for monitoring and performance analysis, not for triggering AutoSupport messages.

D . the SmartSolve tool:

SmartSolve is used for case resolution guidance but does not invoke AutoSupport.

'ONTAP AutoSupport Guide' provides instructions for invoking AutoSupport via CLI and Active IQ.

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

1. Disconnect the cable chains from the chassis

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

2. Evacuate all drives in the drawer

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.

Why Other Options Are Incorrect:

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.

'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.