---
name: "textdump"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/textdump"
---

# textdump(4)

textdump kernel dumping facility

## NAME

**textdump** – textdump kernel dumping facility

## SYNOPSIS

**options** **DDB** **options** **KDB**

**options** **TEXTDUMP\_PREFERRED** **options** **TEXTDUMP\_VERBOSE**

## DESCRIPTION

The **textdump** facility allows the capture of kernel debugging information to disk in a human-readable rather than the machine-readable form normally used with kernel memory dumps and minidumps. This representation, while less complete in that it does not capture full kernel state, can provide debugging information in a more compact, portable, and persistent form than a traditional dump. By combining **textdump** with other [ddb(4)](/ddb/4.md) facilities, such as scripting and output capture, detailed bug information can be captured in a fully automated manner.

## FORMAT

**textdump** data is stored in a dump partition in the same style as a regular memory dump, and will be automatically extracted by [savecore(8)](/savecore/8.md) if present on boot.

**textdump** files are stored in the [tar(5)](/tar/5.md) format, and consist of one or more text files, each storing a particular type of debugging output. The following parts may be present:

- *ddb.txt*

  Captured [ddb(4)](/ddb/4.md) output, if the capture facility has been used. May be disabled by clearing the *debug.ddb.textdump.do\_ddb* sysctl.

- *config.txt*

  Kernel configuration, if **options** **INCLUDE\_CONFIG\_FILE** has been compiled into the kernel. May be disabled by clearing the *debug.ddb.textdump.do\_config* sysctl.

- *msgbuf.txt*

  Kernel message buffer, including recent console output if the capture facility has been used. May be disabled by clearing the *debug.ddb.textdump.do\_msgbuf* sysctl.

- *panic.txt*

  Kernel panic string, if the kernel panicked before the dump was generated. May be disabled by clearing the *debug.ddb.textdump.do\_panic* sysctl.

- *version.txt*

  Kernel version string. My be disabled by clearing the *debug.ddb.textdump.do\_version* sysctl.

Kernel textdumps may be extracted using [tar(1)](/tar/1.md).

## CONFIGURATION

The **textdump** facility is enabled as part of the kernel debugger using **options** **KDB** and **options** **DDB**. By default, kernel dumps generated on panic or via explicit requests for a dump will be regular memory dumps; however, by using the **textdump** **set** command in [ddb(4)](/ddb/4.md), or by setting the *debug.ddb.textdump.pending* sysctl to 1 using [sysctl(8)](/sysctl/8.md), it is possible to request that the next dump be a textdump. One may also directly trigger a textdump in [ddb(4)](/ddb/4.md) by running the command **textdump** **dump**.

If at the [ddb(4)](/ddb/4.md) command line, the commands **textdump** **set**, **textdump** **status**, and **textdump** **unset** may be used to set, query, and clear the textdump pending flag.

As with regular kernel dumps, a dump partition must be automatically or manually configured using [dumpon(8)](/dumpon/8.md).

Additional kernel [config(8)](/config/8.md) options:

- **TEXTDUMP\_PREFERRED**

  sets textdumps to be the default manner of doing dumps. This means there will be no need to [sysctl(8)](/sysctl/8.md) or use the **textdump** **set** [ddb(8)](/ddb/8.md) commands.

- **TEXTDUMP\_VERBOSE**

  will have the textdump facility be more verbose about each file it is emitting as well as other diagnostics useful to debug the textdump facility itself.

## EXAMPLES

In the following example, the script *kdb.enter.panic* will run when the kernel debugger is entered as a result of a panic, enable output capture, dump several useful pieces of debugging information, and then invoke panic in order to force a kernel dump to be written out followed by a reboot:

```
script kdb.enter.panic=textdump set; capture on; show allpcpu; bt;
  ps; alltrace; show alllocks; textdump dump; reset
```

In the following example, the script *kdb.enter.witness* will run when the kernel debugger is entered as a result of a witness violation, printing lock-related information for the user:

```
script kdb.enter.witness=show locks
```

These scripts may also be configured using the [ddb(8)](/ddb/8.md) utility.

## SEE ALSO

[tar(1)](/tar/1.md), [ddb(4)](/ddb/4.md), [tar(5)](/tar/5.md), [ddb(8)](/ddb/8.md), [dumpon(8)](/dumpon/8.md), [savecore(8)](/savecore/8.md), [sysctl(8)](/sysctl/8.md)

## HISTORY

The **textdump** facility first appeared in FreeBSD 7.1.

## AUTHORS

The **textdump** facility was created by Robert N. M. Watson.