Manual: trace-cmd-restore

TRACE-CMD-RESTORE(1)				      libtracefs Manual					TRACE-CMD-RESTORE(1)

NAME
       trace-cmd-restore - restore a failed trace record

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

DESCRIPTION
       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 trace-cmd-report(1).

       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
       -c
	   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
       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
       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), trace-cmd-listen(1)

AUTHOR
       Written by Steven Rostedt, 

RESOURCES
       https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/

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

NOTES
	1. rostedt@goodmis.org
	   mailto:rostedt@goodmis.org

libtracefs						 01/22/2026					TRACE-CMD-RESTORE(1)