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

       -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 2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-20.)  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 to

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

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