---
name: "trace-cmd-restore"
section: "1"
platform: "linux"
package: "trace-cmd"
version: "3.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/trace-cmd-restore"
---

# trace-cmd-restore(1)

restore a failed trace record

## NAME

trace-cmd-restore - restore a failed trace record

## SYNOPSIS

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

## DESCRIPTION

The [trace-cmd(1)](/trace-cmd/1.md) restore command will restore a crashed [trace-cmd-record(1)](/trace-cmd-record/1.md) 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)](/trace-cmd-report/1.md).

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/1.md), [trace-cmd-record(1)](/trace-cmd-record/1.md), [trace-cmd-report(1)](/trace-cmd-report/1.md), [trace-cmd-start(1)](/trace-cmd-start/1.md), [trace-cmd-stop(1)](/trace-cmd-stop/1.md), [trace-cmd-extract(1)](/trace-cmd-extract/1.md), [trace-cmd-reset(1)](/trace-cmd-reset/1.md), [trace-cmd-split(1)](/trace-cmd-split/1.md), [trace-cmd-list(1)](/trace-cmd-list/1.md), [trace-cmd-listen(1)](/trace-cmd-listen/1.md)

## AUTHOR

Written by Steven Rostedt, \<**rostedt@goodmis.org**\[1\]\>

## 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