# lttng-untrack

## NAME



           lttng-untrack - Remove one or more entries from an LTTng resource
           tracker
    


## SYNOPSIS



           **lttng**[_GENERAL OPTIONS_] **untrack**(**--kernel** | **--userspace**)
                 [**--session** =_SESSION_] (**--pid** =_PID_[,_PID_]... | **--all --pid**)
    


## DESCRIPTION



           The **lttng untrack** commands removes one or more entries from a
           resource tracker.
    
           See lttng-track(1) to learn more about LTTng trackers.
    
           The untrack command removes specific resources from a tracker. The
           resources to remove must have been precedently added by
           lttng-track(1). It is also possible to remove all the resources
           from the whitelist using the **--all** option.
    
           As of this version, the only available tracker is the PID tracker.
    
       **Example**
           One common operation is to create a tracing session (see
           lttng-create(1)), remove all the entries from the PID tracker
           whitelist, start tracing, and then manually track PIDs while
           tracing is active.
    
           Assume the maximum system PID is 7 for this example.
    
           Command:
    
               $ lttng create
    
           Initial whitelist:
    
               [0] [1] [2] [3] [4] [5] [6] [7]
    
           Command:
    
               $ lttng untrack --userspace --pid --all
    
           Whitelist:
    
               [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ]
    
           Commands:
    
               $ lttng enable-event --userspace ...
               $ lttng start
               $ # ...
               $ lttng track --userspace --pid=3,5
    
           Whitelist:
    
               [ ] [ ] [ ] [3] [ ] [5] [ ] [ ]
    
           Command:
    
               $ lttng track --userspace --pid=2
    
           Whitelist:
    
               [ ] [ ] [2] [3] [ ] [5] [ ] [ ]
    


## OPTIONS



           General options are described in lttng(1).
    
       **Domain**
           One of:
    
           **-k** , **--kernel**
               Untrack resources tracked in the Linux kernel domain.
    
           **-u** , **--userspace**
               Untrack resources tracked in the user space domain.
    
       **Target**
           **-s** , **--session** =_SESSION_
               Untrack resources in the tracing session named _SESSION_ instead
               of the current tracing session.
    
       **Untracking**
           **-a** , **--all**
               Used in conjunction with an empty **--pid** option: untrack _all_
               process IDs (clear the whitelist).
    
           **-p**[_PID_[,_PID_]...], **--pid**[=_PID_[,_PID_]...]
               Untrack process IDs _PID_ (remove them from the current
               whitelist).
    
               The _PID_ argument must be omitted when also using the **--all**
               option.
    
       **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.
    


## ENVIRONMENT VARIABLES



           **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.
    


## FILES



           **$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.
    


## EXIT STATUS



           **0**
               Success
    
           **1**
               Command error
    
           **2**
               Undefined command
    
           **3**
               Fatal error
    
           **4**
               Command warning (something went wrong during the command)
    


## BUGS



           If you encounter any issue or usability problem, please report it
           on the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-
           tools>.
    


## RESOURCES



           •   LTTng project website <https://lttng.org>
    
           •   LTTng documentation <https://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**
    


## THANKS



           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.
    


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