lttng-crash - Man Page

Recover and read LTTng trace buffers in the event of a crash


lttng-crash [--extract=DIR | --viewer=READER] [-verbose]... SHMDIR


The 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 recovers LTTng trace buffers in the event of a system crash.

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

Without the --extract option

Launches a trace reader (see the --viewer option) to view the recovered traces.

With the --extract=DIR option

Extracts the files as uncorrupted LTTng traces to the DIR directory.

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


-x DIR, --extract=DIR

Extract recovered traces to the directory DIR; do NOT execute any trace reader.

-v,  --verbose

Increase verbosity.

Specify this option up to three times to get more levels of verbosity.

-e READER, --viewer=READER

Use the trace reader READER to read the trace buffers.

READER is the absolute path to the reader command to use, and it can contain command arguments as well. lttng-crash passes the trace directory paths to the READER command as its last arguments.

Without this option, lttng crash uses babeltrace2(1) if it’s available. Otherwise, it tries to use babeltrace(1).

Program information

-h,  --help

Show help.

This option attempts to launch /usr/bin/man to view this manual page. Override the manual pager path with the LTTNG_MAN_BIN_PATH environment variable.


List available command options and quit.

-V,  --version

Show version and quit.

Exit Status






Fatal error



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.

See Also

babeltrace2(1), lttng(1), lttng-create(1)

Referenced By

babeltrace2-source.ctf.fs(7), lttng-create(1).

14 June 2021 LTTng 2.13.11 LTTng Manual