The EMS message wafl.cp.toolong indicates a performance issue where a WAFL Consistent Point (CP) took longer than the allowed threshold. This is typically caused by a heavy, sustained write workload. To investigate and explain this performance event, an administrator would use NetApp's primary performance monitoring tools.

Active IQ Unified Manager is the main tool for historical performance analysis. It collects detailed metrics over time, allowing an administrator to correlate the timestamp of the EMS message with specific workload spikes (IOPS, throughput), latency increases, or high resource utilization (CPU, disk) that caused the long CP.

ONTAP System Manager provides real-time and recent historical performance dashboards directly on the cluster. It can be used for an immediate assessment of the current system state and to review performance charts for the time surrounding the event.

B. Performance Archive: This is the underlying data repository used by Active IQ Unified Manager, not a separate user-facing tool. Selecting Unified Manager (C) implicitly includes the use of its archive.

D. mgwd.log: This log file tracks the management gateway daemon (mgwd), which relates to cluster administration tasks and API calls, not core data-path performance issues like WAFL CPs.

1. Active IQ Unified Manager Documentation: "You can use Unified Manager to monitor your storage objects

identify objects that have performance issues

and troubleshoot the performance events to bring the performance back to the normal range."

Source: NetApp Active IQ Unified Manager 9.10 Documentation

"Monitoring and troubleshooting performance".

2. ONTAP System Manager Documentation: "You can monitor the performance of a cluster and its storage objects by using the performance charts in System Manager... You can view performance data for the last hour up to the last year."

Source: NetApp ONTAP 9.10 System Manager Basics & Administration Guide

"Monitoring storage object performance".

3. ONTAP Troubleshooting Guide: When troubleshooting performance

the guide consistently directs users to analyze performance metrics. "You can use Active IQ Unified Manager to monitor and troubleshoot performance issues... You can also use ONTAP System Manager or the ONTAP CLI to view performance data."

Source: NetApp ONTAP 9.10 Troubleshooting Guide

Section: "Troubleshooting performance problems".