In NetApp ONTAP, when a volume is deleted, it is not immediately purged. Instead, it is moved to a volume recovery queue, which acts as a safety net against accidental deletion. By default, the volume remains in this queue and is available for recovery for a period of 12 hours. After this retention period expires, the system permanently deletes the volume and reclaims its space. This default retention period can be modified by an administrator using the volume recovery-queue modify command.

B. 48 hours: This is a valid, configurable retention period, but it is not the system's default setting.

C. 72 hours: This is a valid, configurable retention period, but it is not the system's default setting.

D. 24 hours: This is a valid, configurable retention period, but it is not the system's default setting.

1. NetApp ONTAP 9.12.1 Documentation, Logical storage management, "Recover a deleted volume" section: "When you delete a volume, it is moved to a recovery queue and retained for a period of time before it is permanently purged from the system. The default retention period is 12 hours."

(Source: NetApp ONTAP 9.12.1 Documentation Center, Logical storage management guide)

2. NetApp ONTAP 9.12.1 Documentation, Command Reference, volume recovery-queue modify command: "The -retention-period parameter specifies the amount of time that deleted volumes are retained in the recovery queue. The default retention period is 12 hours."

(Source: NetApp ONTAP 9.12.1 Documentation Center, ONTAP commands manual page)

When the ONTAP software's background scanner or a read operation detects a logical or structural problem within the WAFL (Write Anywhere File Layout) file system on an aggregate, it triggers a critical Event Management System (EMS) event. The specific event for this condition is wafl.inconsistent.block. By default, this critical event is configured to automatically generate and send a "WAFL INCONSISTENT BLOCK" AutoSupport message to NetApp support. This message alerts administrators and support personnel to a potential file system corruption issue that requires immediate investigation.

A. MEDIUM ERROR DURING RECONSTRUCTION: This message is triggered by a RAID-level event (raid.rg.recons.mediumerror) when a disk encounters read errors during a parity reconstruction, not a WAFL file system inconsistency.

B. CHECKSUM ERROR: While a checksum error can be a symptom of an inconsistency, the specific AutoSupport for it is typically related to the wafl.raid.cksum.mismatch event, which is distinct from a general WAFL structural inconsistency.

C. WAFL INCONSISTENT USER DATA BLOCK: This is not the standard name for the AutoSupport message. The official event wafl.inconsistent.block is more general and covers inconsistencies in both user data and metadata blocks.

1. NetApp ONTAP 9.12.1 EMS event catalog:

Event Name: wafl.inconsistent.block

Description: "WAFL has detected an inconsistent block. This can be a result of a software error or a hardware problem that was not properly detected."

Default Action: This event is classified as severity "CRITICAL" and is configured by default to trigger an AutoSupport notification.

(This official catalog directly links the condition described in the question to the correct answer.)

2. NetApp Technical Report TR-4742: Block Checksums in ONTAP:

Section: "How ONTAP Detects and Corrects Corrupt Data"

Content: The document explains various data protection mechanisms. It differentiates between checksum mismatches (data corruption) and WAFL inconsistencies (file system structural errors). The background WAFL scanner is described as the process that finds inconsistencies, which would trigger the wafl.inconsistent.block event and a corresponding AutoSupport message.

(This source clarifies the distinction between a checksum error (Option B) and a broader WAFL inconsistency.)

NetApp ONTAP systems use a standard naming convention to identify the physical location of a drive. The format is adapter.shelf.bay. In the given drive name, 1.2.3.L1:

1 represents the adapter or channel number.

2 represents the shelf ID.

3 represents the bay number within the shelf.

.L1 indicates the LUN number, which is used for multi-LUN drives but does not change the physical shelf and bay location.

Therefore, the drive is located in shelf 2 and bay 3.

C. The drive is in bay 2.

This is incorrect. The third number in the name (3) indicates the bay number.

D. The drive is in shelf 1.

This is incorrect. The second number in the name (2) indicates the shelf ID.

1. NetApp ONTAP Documentation, "Disk and aggregate management," Section: Overview of disks.

This document states, "Each disk has a unique name that is based on the disk's location: adaptername.shelfid.bayid... shelfid is the ID of the shelf that contains the disk... bayid is the number of the bay in which the disk is located." This directly confirms that the second digit represents the shelf and the third represents the bay.

2. NetApp ONTAP Documentation, "ONTAP 9 Commands: Manual Page Reference," Command: storage disk show.

The documentation for the storage disk show command describes the output for the "Disk" field. It provides examples like node-01:0a.00.7, explaining that the format represents the adapter, shelf, and bay, which aligns with the logic used to determine the correct answer.

The Service Processor (SP) or Baseboard Management Controller (BMC) provides a command-line interface for low-level hardware management. The system fru show command is the primary and most direct method to display detailed inventory information for all installed Field Replaceable Units (FRUs), including part numbers and serial numbers.

The system sensors show command also provides information about FRUs. Its output lists all hardware sensors (e.g., temperature, voltage) and includes a column that explicitly identifies the specific FRU component on which each sensor is located. This makes it a valid, albeit indirect, method for identifying installed FRUs and their operational status.

A. system fru list

This is not a valid command in the official NetApp SP/BMC command-line interface documentation. The correct command to display FRU information is system fru show.

D. system power status

This command is too specific, as it only provides status information for the power supply unit (PSU) FRUs, not a comprehensive list or details about all FRUs.

1. NetApp Service Processor and Baseboard Management Controller CLI Help: This official documentation provides the command reference for the SP/BMC.

Reference for system fru show: Under the system fru command section, it documents system fru show as the command to "Display FRU information for a specific FRU or for all FRUs."

Reference for system sensors show: Under the system sensors command section, it documents system sensors show to "Display the status of all sensors in the system," where the output includes the associated FRU for each sensor.

This reference does not include the command system fru list.

Source: NetApp Documentation, "SP and BMC CLI Help," available on the NetApp Support Site.

2. NetApp ONTAP Hardware and Service Guide (e.g., for AFF A-Series/FAS platforms): These guides detail hardware components and management procedures, including the use of the SP/BMC CLI.

Section: "Using the Service Processor" or "Troubleshooting with the SP CLI". These sections consistently reference system fru show and system sensors show for hardware diagnostics and inventory. For example, in the "Platform monitoring, and troubleshooting guide" for AFF A900/FAS9500, the section on SP commands lists system fru show for FRU information.

Source: Specific hardware platform documentation available on the NetApp Support Site.

On a NetApp AFF A220 system, both the NVMEM battery and the chassis fan are considered Field Replaceable Units (FRUs). The NVMEM battery, housed within the NVMEM module, is critical for protecting data in the non-volatile memory cache during a power loss and is designed for periodic replacement. The chassis fan modules are essential for system cooling and are designed to be hot-swappable, allowing for replacement without system downtime. Official NetApp documentation provides specific procedures for field technicians or customers to replace these components on-site.

B. mSATA boot device: The mSATA boot device is an internal component on the controller module's mainboard and is not designed to be replaced independently in the field. The entire controller module is the FRU.

C. NVME Flash Cache feature: This describes a software-enabled feature, not a distinct hardware component. While the AFF A220 uses NVMe for caching, it is integrated into the controller, not a separate, field-replaceable card.

1. NetApp Documentation: Replace a fan module in an AFF A220 or FAS2750 controller module. This official guide explicitly details the procedure for removing and installing a new fan module, confirming it as an FRU.

Source: NetApp Product Documentation, AFF A220 and FAS2700 Series > Replace parts > Replace a fan module.

2. NetApp Documentation: Replace the NVMEM battery in an AFF A220 or FAS2750 controller. This document provides the step-by-step process for replacing the NVMEM battery, which is part of the NVMEM module, classifying it as an FRU.

Source: NetApp Product Documentation, AFF A220 and FAS2700 Series > Replace parts > Replace the NVMEM battery.

3. NetApp Documentation: Replace a controller module. The procedure for resolving a boot media issue involves replacing the entire controller module, which implicitly confirms that the internal mSATA boot device is not an independent FRU.

Source: NetApp Product Documentation, AFF A220 and FAS2700 Series > Replace parts > Replace a controller module.