NetApp NS0-093 Exam Dumps

If a disk is marked as failed, the Failure Byte on the disk indicates that the disk has been flagged for failure. This can be cleared using the following methods:

1. Reseat the Disk

What it does: Physically remove the disk from the shelf and reseat it. This action can trigger the system to re-evaluate the disk's status and clear the Failure Byte if the failure was transient or due to connection issues.

2. Unfail the Disk

What it does: Using the disk unfail command in maintenance mode clears the Failure Byte and returns the disk to service.

Command Example:

disk unfail <disk_name>

Why Other Options Are Incorrect:

A . Power cycle the disk shelf:

Power cycling the shelf may clear other transient hardware issues but does not specifically clear the Failure Byte.

C . Update the disk firmware:

While updating firmware can prevent future issues, it does not address disks already marked as failed.

NetApp 'Disk Maintenance Guide' explains procedures to address failed disks.

The 'ONTAP Command Reference' covers the disk unfail command for clearing the Failure Byte.

When a volume is deleted in a NetApp ONTAP system, it is placed in the Volume Recovery Queue. By default, the volume remains in this recovery queue for 12 hours before being permanently deleted. This allows administrators to recover mistakenly deleted volumes within the set retention period.

Explanation of Default Behavior:

Volume Recovery Queue:

This is a feature in NetApp ONTAP that acts as a safety mechanism, providing a grace period for recovering deleted volumes.

The default retention period for volumes in the recovery queue is 12 hours, as confirmed by the NetApp KB: 'How to use the Volume Recovery Queue.'

How to Recover a Deleted Volume:

Administrators can recover a deleted volume as long as it remains in the recovery queue and the retention period has not expired.

Use the ONTAP CLI command:

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cluster::> volume recovery-queue recover -vserver <vserver_name> -volume <volume_name>

This command restores the volume back to its original state.

How to Check the Volume Recovery Queue:

To view volumes in the recovery queue and their expiration times, use:

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cluster::> volume recovery-queue show

Changing the Default Retention Period:

While the default period is 12 hours, it can be adjusted by administrators to fit specific organizational requirements. This is done via system settings or policies.

Why the Other Options Are Incorrect:

B . 48 hours: Incorrect. The default retention period is not 48 hours; it is 12 hours by default.

C . 72 hours: Incorrect. While a custom configuration could allow this, it is not the default.

D . 24 hours: Incorrect. Although this was previously thought to be the default, NetApp documentation explicitly states it is 12 hours.

NetApp Knowledge Base Article: 'How to use the Volume Recovery Queue'.

NetApp ONTAP Documentation: Volume Recovery and Data Management Procedures.

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.

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

1. HA-RASTRACE.TGZ

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.

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.

2. SSRAM-LOG

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.

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.

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.