lttng-regenerate(1) — Linux manual page


LTTNG-REGENERATE(1)           LTTng Manual           LTTNG-REGENERATE(1)

NAME         top

       lttng-regenerate - Manage an LTTng tracing session's data

SYNOPSIS         top

       Regenerate the metadata of a session:

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

       Regenerate the state dump of a session:

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

DESCRIPTION         top

       The lttng regenerate command regenerates specific data of a
       tracing session.

       As of this version, the metadata and statedump actions are

   Regenerating a tracing session’s metadata
       The lttng regenerate metadata action can be used to resample the
       offset between the system’s monotonic clock and the wall-clock

       This action is meant to be used to resample the wall-clock time
       following a major NTP
       <> 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.

       If you use lttng-rotate(1) or lttng-enable-rotation(1) to make
       tracing session rotations, this action regenerates the current
       and next trace chunks’s metadata files.

   Regenerating a tracing session’s state dump
       The lttng regenerate statedump action can be used to collect
       up-to-date state dump information during the tracing session.
       This is particularly useful in snapshot (see lttng-snapshot(1))
       or trace file rotation (see lttng-enable-channel(1)) modes where
       the state dump information may be lost.

OPTIONS         top

       General options are described in lttng(1).

       -s SESSION, --session=SESSION
           Regenerate the data 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.

LIMITATIONS         top

       The lttng regenerate metadata 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.


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

           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.

FILES         top

           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)

           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         top


           Command error

           Undefined command

           Fatal error

           Command warning (something went wrong during the command)

BUGS         top

       If you encounter any issue or usability problem, please report it
       on the LTTng bug tracker <

RESOURCES         top

       •   LTTng project website <>

       •   LTTng documentation <>

       •   Git repositories <>

       •   GitHub organization <>

       •   Continuous integration <>

       •   Mailing list <> for support and

       •   IRC channel <irc://>: #lttng on

COPYRIGHTS         top

       This program is part of the LTTng-tools project.

       LTTng-tools is distributed under the GNU General Public License
       version 2 <
       licenses/gpl-2.0.en.html>. See the LICENSE
       <> file
       for details.

THANKS         top

       Special thanks to Michel Dagenais and the DORSAL laboratory
       <> 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.

AUTHORS         top

       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

SEE ALSO         top


COLOPHON         top

       This page is part of the LTTng-Tools (    LTTng tools) project.
       Information about the project can be found at 
       ⟨⟩.  It is not known how to report bugs for this
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       This page was obtained from the project's upstream Git repository
       ⟨git://⟩ on 2019-11-19.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2019-11-14.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
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       (which is not part of the original manual page), send a mail to

LTTng 2.12.0-pre               10/29/2018            LTTNG-REGENERATE(1)

Pages that refer to this page: lttng(1)lttng-metadata(1)