Start-Trace

Getting Started with Start-Trace in PowerShell

Welcome back to Wahmans Powershell blog! Today we’re going to dive into a powerful and somewhat lesser-known cmdlet: Start-Trace. This cmdlet allows you to start an Event Trace logging session, which is a great tool for performance monitoring, troubleshooting, and logging system or application events at a very detailed level.

Definition from Microsoft:
Start-Trace – Starts an Event Trace logging session.

Why use Start-Trace?

Event tracing is a fundamental part of diagnosing and tracking issues at a kernel or application level. Start-Trace enables you to configure and begin a custom event tracing session using ETW (Event Tracing for Windows).

Examples of Using Start-Trace

Example 1: Start a Basic Trace

This is a simple example to start a trace session that logs to a specified file:

Start-Trace -Name "MyTraceSession" -FileMode Circular -MaximumFileSize 50 -LogFilePath "C:\logs\mytrace.etl"

This command initiates a trace session named “MyTraceSession”, storing logs in a circular fashion up to 50MB in the specified log file.

Example 2: Trace Kernel Events

This example enables logging of kernel-level events such as process and thread creation:

Start-Trace -Name "KernelTrace" -LogFilePath "C:\logs\kernel.etl" -EnableKernelFlags Process,Thread,ImageLoad

It starts a session that logs kernel events, which is great for diagnosing low-level system activity.

Example 3: Enable a Provider by GUID

If you have a specific ETW provider you want to trace, such as a custom application or service:

$providerGuid = "{9e814aad-3204-11d2-9a82-006008a86939}"  # Example GUID for System provider
Start-Trace -Name "SystemProviderTrace" -LogFilePath "C:\logs\systemprovider.etl" -ProviderGuid $providerGuid

This command traces events from a specific provider, which is often required when troubleshooting specific subsystems.

Example 4: Advanced Performance Tracing

Here’s a more complex example where you combine user-mode provider and kernel events for full performance analysis:

Start-Trace -Name "FullPerfTrace" -LogFilePath "C:\logs\fullperf.etl" -EnableKernelFlags DiskIO,NetworkTCPIP -ProviderGuid "{3ddfe2de-dec8-4fdb-8d67-92b5b38c42a3}" -Level 5 -MatchAnyKeyword 0x10

This command sets up a comprehensive trace session that includes data from a user-mode provider and kernel network and disk IO.

Wrap-Up

Event tracing can be a seriously powerful tool in your system admin or development toolkit. Start-Trace gives you the power to collect in-depth logs for systems analysis or pinpointing tricky bugs in production or development environments.

Happy scripting, and I will see you in the next post!