diff options
Diffstat (limited to 'Documentation/trace-cmd/trace-cmd-restore.1.txt')
-rw-r--r-- | Documentation/trace-cmd/trace-cmd-restore.1.txt | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/Documentation/trace-cmd/trace-cmd-restore.1.txt b/Documentation/trace-cmd/trace-cmd-restore.1.txt new file mode 100644 index 00000000..ebcbb1b6 --- /dev/null +++ b/Documentation/trace-cmd/trace-cmd-restore.1.txt @@ -0,0 +1,105 @@ +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, <rostedt@goodmis.org> + +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). + |