lttng-clear(1)
===============
:revdate: 2 April 2020

NAME
----
lttng-clear - Clear a tracing session


SYNOPSIS
--------
[verse]
*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *clear* ['SESSION' | option:--all]


DESCRIPTION
-----------
The `lttng clear` command clears one or more tracing sessions, that is,
it deletes the contents of their tracing buffers and all their local and
streamed trace data.

If no options are specified, the current tracing session is cleared
(see man:lttng-create(1) for more information about the current
tracing session).

If 'SESSION' is specified, the existing tracing session named 'SESSION'
is cleared.

With the option:--all option, *all* the tracing sessions, as listed in
the output of `lttng list` (see man:lttng-list(1)), are cleared.

If a tracing session is configured in snapshot mode (see the
man:lttng-create(1) command's nloption:--snapshot option), only the
tracing buffers are cleared.

For a given tracing session, if at least one rotation occurred (see
man:lttng-rotate(1)), only its tracing buffers and its current trace
chunk are cleared; its archived trace chunks are :not: cleared.

NOTE: The nloption:--disallow-clear option and the
`LTTNG_RELAYD_DISALLOW_CLEAR` environment variable of
man:lttng-relayd(8) can disable remote clearing operations. If LTTng
sends tracing data over the network for 'SESSION' (or for any tracing
session with the option:--all option) to a relay daemon configured as
such, `lttng clear` fails.


include::common-cmd-options-head.txt[]


Target
~~~~~~
option:-a, option:--all::
    Clear all the tracing sessions instead of the current tracing
    session or the tracing session named 'SESSION'.


include::common-cmd-help-options.txt[]


include::common-cmd-footer.txt[]


SEE ALSO
--------
man:lttng-create(1),
man:lttng-rotate(1),
man:lttng-set-session(1),
man:lttng-relayd(8),
man:lttng(1)
