How to troubleshoot DTrace

In the unlikely event that you experience problems when you run DTrace, Table: Potential DTrace problems gives instructions on how to resolve them.

Table: Potential DTrace problems

Problem	What to do
Lines being skipped.	The first figure on each trace line is the sequence number as it was captured. If there is insufficient CPU time available to process and write entries to the log file, DTrace may skip some lines. If you are tracing an agent task, try to lower the number of threads for the task and monitor a single thread only. If there are multiple tasks of the same type (for example, Archiving), stop all but one of them. DTrace does not differentiate between the different services.
No output on the screen after monitor command, or no trace in log file.	Ensure that you have selected the correct processes for DTracing. If you are running DTrace over Terminal Services or another remote control application that does not use the primary operating system console, note that DTrace events are written to the primary console and so may not appear when using Terminal Services. In Enterprise Vault, a message is posted in the log file to say that Terminal Services was used.
Too much information in the log file.	You can filter and trigger DTrace content based on specific words or events. If you need to focus on the root cause of a problem, you can also limit the number of processes and threads that you monitor.

Problem

What to do

Lines being skipped.

The first figure on each trace line is the sequence number as it was captured. If there is insufficient CPU time available to process and write entries to the log file, DTrace may skip some lines. If you are tracing an agent task, try to lower the number of threads for the task and monitor a single thread only.

If there are multiple tasks of the same type (for example, Archiving), stop all but one of them. DTrace does not differentiate between the different services.

No output on the screen after monitor command, or no trace in log file.

Ensure that you have selected the correct processes for DTracing. If you are running DTrace over Terminal Services or another remote control application that does not use the primary operating system console, note that DTrace events are written to the primary console and so may not appear when using Terminal Services. In Enterprise Vault, a message is posted in the log file to say that Terminal Services was used.

Too much information in the log file.

You can filter and trigger DTrace content based on specific words or events. If you need to focus on the root cause of a problem, you can also limit the number of processes and threads that you monitor.