syslog-ng-debun(1)

Usage

syslog-ng-debun [options]

Overview

NOTE: The syslog-ng-debun application is distributed with the syslog-ng OSE system logging application, and is usually part of the syslog-ng OSE package. The latest version of the syslog-ng OSE application is available at the syslog-ng OSE page.

This manual page is only an abstract.

The syslog-ng-debun tool collects and saves information about your syslog-ng OSE installation, making troubleshooting easier, especially if you ask help about your syslog-ng OSE related problem.

Options

-r
Run syslog-ng-debun. Using this option is required to actually
execute the data collection with syslog-ng-debun. It is needed to
prevent accidentally running syslog-ng-debun.

-h
Display the help page.

-l
Do not collect privacy-sensitive data, for example, process tree,
fstab, and so on. If you use with -d, then the following parameters
will be used for debug mode:-Fev

-R <directory>
The directory where syslog-ng PE is installed instead of
/opt/syslog-ng.

-W <directory>
Set the working directory, where the debug bundle will be saved.
Default value: /tmp. The name of the created file is
syslog.debun.${host}.${date}.${3-random-characters-or-pid}.tgz

Options

-d
Start syslog-ng OSE in debug mode, using the -Fedv --enable-core
options.

![](/assets/images/caution.png) **CAUTION:**
Using this option under high message load may increase disk I/O
during the debug, and the resulting debug bundle can be huge. To exit debug
mode, press Enter.

-D <options>
Start syslog-ng OSE in debug mode, using the specified command-line
options. To exit debug mode, press Enter.

-t <seconds>
Run syslog-ng OSE in noninteractive debug mode for <seconds>, and
automatically exit debug mode after the specified number of seconds.

-w <seconds>
Wait <seconds> seconds before starting debug mode.

System call tracing

-s
Enable syscall tracing (strace -f or truss -f). Note that using -s
itself does not enable debug mode, only traces the system calls of
an already running syslog-ng OSE process. To trace system calls in
debug mode, use both the -s and -d options.

Options

Capturing packets requires a packet capture tool on the host. The syslog-ng-debun tool attempts to use tcpdump on most platforms, except for Solaris, where it uses snoop.

-i <interface>
Capture packets only on the specified interface, for example, eth0.

-p
Capture incoming packets using the following filter: port 514 or
port 601 or port 53

-P <options>
Capture incoming packets using the specified filter.

-t <seconds>
Run syslog-ng OSE in noninteractive debug mode for <seconds>, and
automatically exit debug mode after the specified number of seconds.

Examples:

syslog-ng-debun -r

Create a simple debug bundle, collecting information about your environment, for example, list packages containing the word: syslog, ldd of your syslog-binary, and so on.

syslog-ng-debun -r -l

Similar to syslog-ng-debun -r, but without privacy-sensitive information. For example, the following is NOT collected: fstab, df output, mount info, ip / network interface configuration, DNS resolv info, and process tree.

syslog-ng-debun -r -d

Similar to syslog-ng-debun -r, but it also stops syslog-ng OSE, then restarts it in debug mode (-Fedv --enable-core). To stop debug mode, press Enter. The output of the debug mode collected into a separate file, and also added to the debug bundle.

syslog-ng-debun -r -s

Trace the system calls (using strace or truss) of an already running syslog-ng OSE process.

syslog-ng-debun -r -d -s

Restart syslog-ng OSE in debug mode, and also trace the system calls (using strace or truss) of the syslog-ng OSE process.

syslog-ng-debun -r -p

Run packet capture (pcap) with the filter: port 514 or port 601 or port 53 Also waits for pressing Enter, like debug mode.

syslog-ng-debun -r -p -t 10

Noninteractive debug mode: Similar to syslog-ng-debun -r -p, but automatically exit after 10 seconds.

syslog-ng-debun -r -P "host 1.2.3.4"  -D "-Fev --enable-core"

Change the packet-capturing filter from the default to host 1.2.3.4. Also change debugging parameters from the default to -Fev --enable-core. Since a timeout (-t) is not given, waits for pressing Enter.

syslog-ng-debun -r -p -d -w 5 -t 10

Collect pcap and debug mode output following this scenario:

•: Start packet capture with default parameters (-p)

•: Wait 5 seconds (-w 5)

•: Stop syslog-ng

•: Start syslog-ng OSE in debug mode with default parameters (-d)

•: Wait 10 seconds (-t 10)

•: Stop syslog-ng OSE debuging

•: Start syslog-ng OSE

•: Stop packet capturing

Files

/Users/hofi/Develop/Balabit/syslog-ng/build/install/bin/loggen

NOTE: If you experience any problems or need help with syslog-ng OSE, see the syslog-ng OSE Administration Guide[1], or visit the syslog-ng OSE mailing list[2]. For news and notifications about syslog-ng OSE, visit the syslog-ng OSE blogs[3].

Notes

[1] syslog-ng OSE Administration Guide
⟨https://syslog-ng.github.io/admin-guide/README⟩

[2] syslog-ng OSE mailing list
⟨https://lists.balabit.hu/mailman/listinfo/syslog-ng⟩

[3] syslog-ng OSE blogs
⟨https://syslog-ng.com/blog/⟩

History

Arch Linux 2026-11-01: the text shown here
Debian 13 (Trixie)
Debian 12 (Bookworm)
Debian 11 (Bullseye)
Debian 10 (Buster)

-D until Debian 13 (Trixie); -P until Debian 13 (Trixie); -R until Debian 13 (Trixie); -W until Debian 13 (Trixie); -d until Debian 13 (Trixie); -h until Debian 13 (Trixie); -i until Debian 13 (Trixie); -l until Debian 13 (Trixie); -p until Debian 13 (Trixie); -r until Debian 13 (Trixie); -t until Debian 13 (Trixie); -w until Debian 13 (Trixie).