WHM Server Performance Issue with Low CPU Load

20.01.2026

A WHM server was experiencing significant performance issues despite low CPU load. I analyzed the system at service, disk, and network levels to identify the root cause and restore stable performance.

Problem

The server showed low CPU usage, yet websites were responding slowly and users reported performance degradation.

Analysis & Actions Taken

  • Checked CPU, memory, and load averages

  • Analyzed disk I/O wait and filesystem performance

  • Reviewed Apache / PHP-FPM / MySQL behavior

  • Inspected Keep-Alive and timeout configurations

  • Scanned for external requests and mixed HTTP/HTTPS content

  • Identified blocking calls affecting request handling

    • Root Cause

    The performance issue was caused by non-CPU-related bottlenecks, primarily I/O and service-level configuration inefficiencies.

    Result

    After optimization, the server achieved stable response times, improved request handling, and consistent performance without increasing resource usage.
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