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


NAME
----
lttng-crash - Recover and view LTTng 2 trace buffers in the event of a crash


SYNOPSIS
--------
[verse]
*lttng-crash* [option:--extract='PATH' | option:--viewer='VIEWER'] [option:-v | option:-vv | option:-vvv] 'SHMDIR'


DESCRIPTION
-----------
The https://lttng.org/[_Linux Trace Toolkit: next generation_] is an open
source software package used for correlated tracing of the Linux kernel,
user applications, and user libraries.

LTTng consists of Linux kernel modules (for Linux kernel tracing) and
dynamically loaded libraries (for user application and library tracing).

The `lttng-crash` command-line tool is used to recover and view
LTTng trace buffers in the event of a system crash.

`lttng-crash` reads files within the directory 'SHMDIR' and does one
of:

Without the option:--extract option::
    Launches a trace reader (see the option:--viewer option) to view the
    recovered traces.

With the option:--extract option::
    Extracts them as uncorrupted LTTng traces on the file system.

'SHMDIR' is the directory specified as the argument of the
nloption:--shm-path option of the man:lttng-create(1) command used to
create the tracing session for which to recover the traces.


OPTIONS
-------
option:-x 'PATH', option:--extract='PATH'::
    Extract recovered traces to path 'PATH'; do not execute the trace
    viewer.

option:-v, option:--verbose::
    Increase verbosity.
+
Three levels of verbosity are available, which are triggered by
appending additional `v` letters to the option
(that is, `-vv` and `-vvv`).

option:-e 'VIEWER', option:--viewer='VIEWER'::
    Use trace viewer 'VIEWER' to view the trace buffers. 'VIEWER' is the
    absolute path to the viewer command to use, and it can contain
    command arguments as well. The trace directory paths are passed to
    the 'VIEWER' command as its last arguments.
+
Without this option, `lttng crash` uses man:babeltrace2(1) if it's
available. Otherwise, it tries to use man:babeltrace(1).


Program information
~~~~~~~~~~~~~~~~~~~
option:-h, option:--help::
    Show help.

option:-V, option:--version::
    Show version.


EXIT STATUS
-----------
*0*::
    Success

*1*::
    Error

*3*::
    Fatal error


include::common-footer.txt[]


SEE ALSO
--------
man:lttng(1),
man:lttng-sessiond(8),
man:lttng-relayd(8),
man:lttng-ust(3),
man:babeltrace2(1)
