NS0-093 Exam Dumps : NetApp Accredited Hardware Support Engineer

A. Ignoring NetApp Active IQ health risks

Explanation:NetApp Active IQ provides proactive monitoring and alerts for system health risks, including risks related to WAFL inconsistencies. Ignoring these alerts can lead to unresolved issues such as metadata corruption, hardware failures, or system misconfigurations, increasing the chances of WAFL inconsistencies.

Examples of Active IQ Risks:

Disk health warnings.

High write latency or metadata bottlenecks.

Aggregates running out of space.

C. Using outdated disk firmware

Explanation:Outdated disk firmware can cause performance issues, drive failures, or incorrect handling of I/O operations, potentially leading to WAFL inconsistencies. Disk firmware updates often include fixes for critical issues that improve reliability and prevent data corruption.

Importance:Keeping firmware updated ensures compatibility with ONTAP and minimizes risks of disk-level errors that can propagate to WAFL.

Why the Other Options Are Incorrect:

B. Constantly running at high load:

Running at high load can impact performance but does not directly cause WAFL inconsistencies. WAFL is designed to handle high I/O loads efficiently.

D. Upgrading frequently:

Frequent upgrades, when performed correctly, do not increase the chances of WAFL inconsistencies. However, improperly executed upgrades or skipping recommended steps might introduce risks.

References:

NetApp Knowledge Base: Articles on Active IQ health checks and disk firmware management.

ONTAP System Administration Guide: Recommendations for preventing WAFL inconsistencies.

 Understanding a Single PHY Down Issue:

In SAS environments, a PHY represents a physical layer connection between devices.

When a single PHY reports a "down" status, it typically indicates an issue with the physical connectivity or the associated hardware.

 Cause 1: Improperly Seated Cable

If the SAS cable is not properly seated in the port, the connection for one or more PHYs may fail.

Reseating the cable on both ends (controller and shelf) often resolves the issue.

 Cause 2: Defective Cable

A damaged or faulty SAS cable can cause PHY errors.

Replacing the cable and verifying the connection resolves the issue in this case.

 Why Other Options Are Not Likely:

B. Outdated IOM firmware: While outdated firmware can cause other issues, it rarely affects only a single PHY.

D. Offline shelf: If an entire shelf is offline, more than one PHY would typically be affected, as multiple connections are involved in SAS stacks.

 NetApp Reference Documentation:

Found in the "ONTAP SAS Cabling Guide" and "Shelf Troubleshooting Guide". These documents detail troubleshooting for PHY errors and common SAS hardware issues.

 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.