When troubleshooting poor Virtual Machine (VM) performance, the initial analysis should focus on the most common resource bottlenecks: CPU and storage.

CPU ready time is a critical hypervisor metric indicating the percentage of time a VM was ready to execute instructions but had to wait for a physical CPU to become available. High ready time directly points to CPU contention, a primary cause of sluggishness.

Disk IOPS latency measures the time it takes for the underlying storage system to service an I/O request. High storage latency is a major bottleneck for applications, causing the VM to wait for data and appear unresponsive.

These two metrics provide immediate insight into the most frequent causes of performance degradation.

C. Tape backup speed: This measures the performance of a specific background task (backup) and is not a primary, real-time indicator of a VM's general interactive performance.

D. Switch LED status: This indicates basic physical layer network connectivity and activity. It does not provide performance metrics like latency or packet loss required for troubleshooting.

1. VMware vSphere Documentation, "vSphere Monitoring and Performance", Section: "CPU Performance Counters": This official guide details the %RDY (Ready) counter, explaining that a consistently high value (e.g., >5%) indicates the VM is frequently waiting for CPU resources, which can cause significant performance issues. This directly supports the selection of "CPU ready time".

2. VMware vSphere Documentation, "Performance Troubleshooting for VMware vSphere 6.7", Page 43, Section: "Troubleshooting Storage Performance Problems": This document explicitly states, "The most important storage performance counters are latency and IOPS." It further details how to use esxtop to monitor disk latency (DAVG/cmd), confirming that disk I/O latency is a fundamental starting point for storage performance analysis.

3. HPE White Paper, "HPE Reference Architecture for VMware Horizon on HPE SimpliVity 380 Gen10", Page 28, Section: "Monitoring": While discussing overall solution health, this document emphasizes monitoring key performance indicators, stating, "Monitor storage latency from the vSphere Client... High latency can cause poor user experience." This validates that within an HPE ecosystem, storage latency is a primary metric for performance analysis.