How can the architect identify if the server OS machines are the source of a bottleneck?

While CPU and memory consumption are important general metrics, disk I/O and page file utilization are more specific and common bottlenecks for server OS machines, especially in virtualized environments.

Memory and network utilization are relevant, but high disk I/O, often accompanied by page file usage, is a more typical and impactful bottleneck for OS machines handling user sessions.

While disk and network I/O are important, page file utilization is a crucial indicator of memory pressure, which often drives excessive disk I/O on server OS machines and is a more specific bottleneck indicator.

Server OS machines, especially in virtual desktop infrastructure or terminal server environments, frequently experience high disk I/O due to user profile writes, application activity, and write cache operations, and excessive page file utilization directly signals memory pressure causing the system to swap to disk.