#### 5.9.1.2 Creating Trace Files

 If the [**mysqld**](mysqld.html) server does not start or it crashes easily, you can try to create a trace file to find the problem.

 To do this, you must have a [**mysqld**](mysqld.html) that has been compiled with debugging support. You can check this by executing `mysqld -V`. If the version number ends with `-debug`, it is compiled with support for trace files. (On Windows, the debugging server is named [**mysqld-debug**](mysqld.html) rather than [**mysqld**](mysqld.html).)

 Start the [**mysqld**](mysqld.html) server with a trace log in `/tmp/mysqld.trace` on Unix or `\mysqld.trace` on Windows:

```
$> mysqld --debug
```

 On Windows, you should also use the [`--standalone`](server-options.html#option_mysqld_standalone) flag to not start [**mysqld**](mysqld.html) as a service. In a console window, use this command:

```
C:\> mysqld-debug --debug --standalone
```

 After this, you can use the `mysql.exe` command-line tool in a second console window to reproduce the problem. You can stop the [**mysqld**](mysqld.html) server with [**mysqladmin shutdown**](mysqladmin.html).

 The trace file can become **very large**! To generate a smaller trace file, you can use debugging options something like this:

[**mysqld --debug=d,info,error,query,general,where:O,/tmp/mysqld.trace**](mysqld.html)

 This only prints information with the most interesting tags to the trace file.

 If you file a bug, please add only those lines from the trace file to the bug report that indicate where something seems to go wrong. If you cannot locate the wrong place, open a bug report and upload the whole trace file to the report, so that a MySQL developer can take a look at it. For instructions, see [Section 1.6, “How to Report Bugs or Problems”](bug-reports.html).

 The trace file is made with the **DBUG** package by Fred Fish. See [Section 5.9.4, “The DBUG Package”](dbug-package.html).

