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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT VARIABLES | FILES | EXIT STATUS | BUGS | RESOURCES | COPYRIGHTS | THANKS | AUTHORS | SEE ALSO | COLOPHON |
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LTTNG-START(1) LTTng Manual LTTNG-START(1)
lttng-start - Start LTTng tracers
lttng [GENERAL OPTIONS] start [SESSION]
The lttng start command starts the various LTTng tracers for a given
inactive tracing session.
Starting the LTTng tracers has the effect that all enabled event
rules within enabled channels can make their target event sources
emit trace events. Whether they are recorded to the local file
system, sent over the network, or not recorded at all depends on the
specific configuration of the tracing session in which tracing is
started. See lttng-create(1) for different session modes.
A tracing session with running tracers is said to be active. Active
tracing sessions can return to the inactive state using the
lttng-stop(1) command.
If SESSION is omitted, the LTTng tracers are started for the current
tracing session (see lttng-create(1) for more information about the
current tracing session). Otherwise, they are started for the
existing tracing session named SESSION. lttng list outputs all the
existing tracing sessions (see lttng-list(1)).
General options are described in lttng(1).
Program information
-h, --help
Show command help.
This option, like lttng-help(1), attempts to launch /usr/bin/man
to view the command’s man page. The path to the man pager can be
overridden by the LTTNG_MAN_BIN_PATH environment variable.
--list-options
List available command options.
LTTNG_ABORT_ON_ERROR
Set to 1 to abort the process after the first error is
encountered.
LTTNG_HOME
Overrides the $HOME environment variable. Useful when the user
running the commands has a non-writable home directory.
LTTNG_MAN_BIN_PATH
Absolute path to the man pager to use for viewing help
information about LTTng commands (using lttng-help(1) or lttng
COMMAND --help).
LTTNG_SESSION_CONFIG_XSD_PATH
Path in which the session.xsd session configuration XML schema
may be found.
LTTNG_SESSIOND_PATH
Full session daemon binary path.
The --sessiond-path option has precedence over this environment
variable.
Note that the lttng-create(1) command can spawn an LTTng session
daemon automatically if none is running. See lttng-sessiond(8) for
the environment variables influencing the execution of the session
daemon.
$LTTNG_HOME/.lttngrc
User LTTng runtime configuration.
This is where the per-user current tracing session is stored
between executions of lttng(1). The current tracing session can
be set with lttng-set-session(1). See lttng-create(1) for more
information about tracing sessions.
$LTTNG_HOME/lttng-traces
Default output directory of LTTng traces. This can be overridden
with the --output option of the lttng-create(1) command.
$LTTNG_HOME/.lttng
User LTTng runtime and configuration directory.
$LTTNG_HOME/.lttng/sessions
Default location of saved user tracing sessions (see
lttng-save(1) and lttng-load(1)).
/usr/local/etc/lttng/sessions
System-wide location of saved tracing sessions (see lttng-save(1)
and lttng-load(1)).
Note
$LTTNG_HOME defaults to $HOME when not explicitly set.
0
Success
1
Command error
2
Undefined command
3
Fatal error
4
Command warning (something went wrong during the command)
If you encounter any issue or usability problem, please report it on
the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-tools>.
· LTTng project website <http://lttng.org>
· LTTng documentation <http://lttng.org/docs>
· Git repositories <http://git.lttng.org>
· GitHub organization <http://github.com/lttng>
· Continuous integration <http://ci.lttng.org/>
· Mailing list <http://lists.lttng.org> for support and
development: lttng-dev@lists.lttng.org
· IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
This program is part of the LTTng-tools project.
LTTng-tools is distributed under the GNU General Public License
version 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>.
See the LICENSE <https://github.com/lttng/lttng-
tools/blob/master/LICENSE> file for details.
Special thanks to Michel Dagenais and the DORSAL laboratory
<http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal
for the LTTng journey.
Also thanks to the Ericsson teams working on tracing which helped us
greatly with detailed bug reports and unusual test cases.
LTTng-tools was originally written by Mathieu Desnoyers, Julien
Desfossez, and David Goulet. More people have since contributed to
it.
LTTng-tools is currently maintained by Jérémie Galarneau
<mailto:jeremie.galarneau@efficios.com>.
lttng-stop(1), lttng(1)
This page is part of the LTTng-Tools ( LTTng tools) project.
Information about the project can be found at ⟨http://lttng.org/⟩.
It is not known how to report bugs for this man page; if you know,
please send a mail to man-pages@man7.org. This page was obtained
from the project's upstream Git repository
⟨git://git.lttng.org/lttng-tools.git⟩ on 2018-02-02. (At that time,
the date of the most recent commit that was found in the repository
was 2018-02-01.) If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-to-
date source for the page, or you have corrections or improvements to
the information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org
LTTng 2.11.0-pre 02/02/2018 LTTNG-START(1)
Pages that refer to this page: lttng(1), lttng-disable-event(1), lttng-enable-event(1), lttng-snapshot(1), lttng-stop(1)