| 1 | --- |
| 2 | id: basic-tracing-session-control |
| 3 | --- |
| 4 | |
| 5 | Once you have |
| 6 | [created a tracing session](#doc-creating-destroying-tracing-sessions) |
| 7 | and [enabled one or more events](#doc-enabling-disabling-events), |
| 8 | you may activate the LTTng tracers for the current tracing session at |
| 9 | any time: |
| 10 | |
| 11 | <pre class="term"> |
| 12 | lttng start |
| 13 | </pre> |
| 14 | |
| 15 | Subsequently, you may stop the tracers: |
| 16 | |
| 17 | <pre class="term"> |
| 18 | lttng stop |
| 19 | </pre> |
| 20 | |
| 21 | LTTng is very flexible: user space applications may be launched before |
| 22 | or after the tracers are started. Events are only recorded if they |
| 23 | are properly enabled and if they occur while tracers are active. |
| 24 | |
| 25 | A tracing session name may be passed to both the `start` and `stop` |
| 26 | commands to start/stop tracing a session other than the current one. |