lttng-metadata man page

lttng-metadata — Manage an LTTng tracing session's metadata generation


lttng [GENERAL OPTIONS] metadata regenerate [--session=SESSION]


The lttng metadata command manages a tracing session’s metadata generation options.

As of this version, only the regenerate command’s action is available. Regenerating a tracing session’s metadata can be used to resample the offset between the system’s monotonic clock and the wall-clock time.

This command is meant to be used to resample the wall-clock time following a major NTP <https://en.wikipedia.org/wiki/Network_T…> correction. As such, a system booting with an incorrect wall time can be traced before its wall time is NTP-corrected. Regenerating the tracing session’s metadata ensures that trace viewers can accurately determine the events time relative to Unix Epoch.


General options are described in lttng(1).

-s, --session=SESSION
Manage the metadata generation of the tracing session named SESSION instead of the current tracing session.

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 available command options.


The lttng metadata regenerate command can only be used on kernel and user space tracing sessions (using per-user buffering), in non-live mode.

See lttng-enable-channel(1) for more information about buffering schemes and lttng-create(1) for more information about the different tracing session modes.

Environment Variables


Set to 1 to abort the process after the first error is encountered.


Overrides the $HOME environment variable. Useful when the user running the commands has a non-writable home directory.


Absolute path to the man pager to use for viewing help information about LTTng commands (using lttng-help(1) or lttng COMMAND --help).


Path in which the session.xsd session configuration XML schema may be found.


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.



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.


Default output directory of LTTng traces. This can be overridden with the --output option of the lttng-create(1) command.


User LTTng runtime and configuration directory.


Default location of saved user tracing sessions (see lttng-save(1) and lttng-load(1)).


System-wide location of saved tracing sessions (see lttng-save(1) and lttng-load(1)).


$LTTNG_HOME defaults to $HOME when not explicitly set.

Exit Status




Command error


Undefined command


Fatal error


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-t…>.


· 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-license…>. See the LICENSE <https://github.com/lttng/lttng-tools/bl…> 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>.

See Also


Referenced By


Explore man page connections for lttng-metadata(1).

LTTng 2.8.2 10/11/2016