trace-cmd-restore(1) — Linux manual page


TRACE-CMD-RESTORE(1)                                    TRACE-CMD-RESTORE(1)

NAME         top

       trace-cmd-restore - restore a failed trace record

SYNOPSIS         top

       trace-cmd restore [OPTIONS] [command] cpu-file [cpu-file ...]

DESCRIPTION         top

       The trace-cmd(1) restore command will restore a crashed
       trace-cmd-record(1) file. If for some reason a trace-cmd record
       fails, it will leave a the per-cpu data files and not create the
       final trace.dat file. The trace-cmd restore will append the files to
       create a working trace.dat file that can be read with

       When trace-cmd record runs, it spawns off a process per CPU and
       writes to a per cpu file usually called trace.dat.cpuX, where X
       represents the CPU number that it is tracing. If the -o option was
       used in the trace-cmd record, then the CPU data files will have that
       name instead of the trace.dat name. If a unexpected crash occurs
       before the tracing is finished, then the per CPU files will still
       exist but there will not be any trace.dat file to read from.
       trace-cmd restore will allow you to create a trace.dat file with the
       existing data files.

OPTIONS         top

           Create a partial trace.dat file from the machine, to be used with
           a full trace-cmd restore at another time. This option is useful
           for embedded devices. If a server contains the cpu files of a
           crashed trace-cmd record (or trace-cmd listen), trace-cmd restore
           can be executed on the embedded device with the -c option to get
           all the stored information of that embedded device. Then the file
           created could be copied to the server to run the trace-cmd
           restore there with the cpu files.

               If *-o* is not specified, then the file created will be called
               'trace-partial.dat'. This is because the file is not a full version
               of something that trace-cmd-report(1) could use.

       -t tracing_dir
           Used with -c, it overrides the location to read the events from.
           By default, tracing information is read from the debugfs/tracing
           directory.  -t will use that location instead. This can be useful
           if the trace.dat file to create is from another machine. Just tar
           -cvf events.tar debugfs/tracing and copy and untar that file
           locally, and use that directory instead.

       -k kallsyms
           Used with -c, it overrides where to read the kallsyms file from.
           By default, /proc/kallsyms is used.  -k will override the file to
           read the kallsyms from. This can be useful if the trace.dat file
           to create is from another machine. Just copy the /proc/kallsyms
           file locally, and use -k to point to that file.

       -o output'
           By default, trace-cmd restore will create a trace.dat file (or
           trace-partial.dat if -c is specified). You can specify a
           different file to write to with the -o option.

       -i input
           By default, trace-cmd restore will read the information of the
           current system to create the initial data stored in the trace.dat
           file. If the crash was on another machine, then that machine
           should have the trace-cmd restore run with the -c option to
           create the trace.dat partial file. Then that file can be copied
           to the current machine where trace-cmd restore will use -i to
           load that file instead of reading from the current system.

EXAMPLES         top

       If a crash happened on another box, you could run:

           $ trace-cmd restore -c -o box-partial.dat

       Then on the server that has the cpu files:

           $ trace-cmd restore -i box-partial.dat trace.dat.cpu0 trace.dat.cpu1

       This would create a trace.dat file for the embedded box.

SEE ALSO         top

       trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1),
       trace-cmd-start(1), trace-cmd-stop(1), trace-cmd-extract(1),
       trace-cmd-reset(1), trace-cmd-split(1), trace-cmd-list(1),

AUTHOR         top

       Written by Steven Rostedt, <[1]>

RESOURCES         top


COPYING         top

       Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted
       under the terms of the GNU Public License (GPL).

NOTES         top


COLOPHON         top

       This page is part of the trace-cmd (a front-end for Ftrace) project.
       Information about the project can be found at [unknown -- if you
       know, please contact] If you have a bug report for
       this manual page, send it to Steven Rostedt <>.
       This page was obtained from the project's upstream Git repository
       on 2020-11-01.  (At that time, the date of the most recent commit
       that was found in the repository was 2020-10-06.)  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail

                                 05/27/2020             TRACE-CMD-RESTORE(1)

Pages that refer to this page: trace-cmd(1)