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, <[email protected][1]>

RESOURCES

   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/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. [email protected]
       mailto:[email protected]

                              07/17/2016              TRACE-CMD-RESTORE(1)

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