How can you see system performance metrics?

The best approach to viewing system performance metrics includes the use of commands specifically designed for monitoring and reporting on different aspects of system performance. The vmstat command provides metrics related to system processes, memory, paging, block I/O, traps, and CPU activity, giving a comprehensive overview of system health. Likewise, the iostat command focuses on input/output statistics for devices and partitions, helping to observe the performance of the storage subsystem.

While the top command is indeed a commonly used tool for real-time system monitoring, focusing on processes and their CPU and memory usage, it is typically categorized separately due to its interactive nature and extensive details on active processes. The perf command is powerful for profiling and tracing system performance but is more complex and geared towards performance analysis rather than just simple metrics. The stat command does not provide performance metrics on its own in a way that is immediately useful for system monitoring.

In summary, using vmstat or iostat effectively gives you clear insights into various system performance metrics, making option B the appropriate choice.