NS0-093 Exam Dumps - Netapp NAHSE Questions and Answers

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:

 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.

 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 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: