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author | Lennart Poettering <lennart@poettering.net> | 2019-07-29 09:24:09 +0200 |
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committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2019-07-29 09:59:18 +0200 |
commit | 77ce88c1286311e6f190f76c9d5cd6beff223989 (patch) | |
tree | 03ee66bd77e62fbf7f866f6161b30ff361607110 /man | |
parent | news corrections and improvements (#13200) (diff) | |
download | systemd-77ce88c1286311e6f190f76c9d5cd6beff223989.tar.xz systemd-77ce88c1286311e6f190f76c9d5cd6beff223989.zip |
man: document the kernel command line options to use when logging to kmsg
Prompted by:
https://lists.freedesktop.org/archives/systemd-devel/2019-July/043149.html
Diffstat (limited to 'man')
-rw-r--r-- | man/journald.conf.xml | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/man/journald.conf.xml b/man/journald.conf.xml index 57c2256567..44fd0d2f3d 100644 --- a/man/journald.conf.xml +++ b/man/journald.conf.xml @@ -288,21 +288,25 @@ <term><varname>ForwardToConsole=</varname></term> <term><varname>ForwardToWall=</varname></term> - <listitem><para>Control whether log messages received by the journal daemon shall - be forwarded to a traditional syslog daemon, to the kernel log buffer (kmsg), to - the system console, or sent as wall messages to all logged-in users. These - options take boolean arguments. If forwarding to syslog is enabled but nothing - reads messages from the socket, forwarding to syslog has no effect. By default, - only forwarding to wall is enabled. These settings may be overridden at boot time - with the kernel command line options - <literal>systemd.journald.forward_to_syslog</literal>, + <listitem><para>Control whether log messages received by the journal daemon shall be forwarded to a + traditional syslog daemon, to the kernel log buffer (kmsg), to the system console, or sent as wall + messages to all logged-in users. These options take boolean arguments. If forwarding to syslog is + enabled but nothing reads messages from the socket, forwarding to syslog has no effect. By default, + only forwarding to wall is enabled. These settings may be overridden at boot time with the kernel + command line options <literal>systemd.journald.forward_to_syslog</literal>, <literal>systemd.journald.forward_to_kmsg</literal>, <literal>systemd.journald.forward_to_console</literal>, and - <literal>systemd.journald.forward_to_wall</literal>. If the option name is - specified without <literal>=</literal> and the following argument, true is - assumed. Otherwise, the argument is parsed as a boolean. When forwarding to the - console, the TTY to log to can be changed with <varname>TTYPath=</varname>, - described below.</para></listitem> + <literal>systemd.journald.forward_to_wall</literal>. If the option name is specified without + <literal>=</literal> and the following argument, true is assumed. Otherwise, the argument is parsed + as a boolean.</para> + + <para>When forwarding to the console, the TTY to log to can be changed with + <varname>TTYPath=</varname>, described below.</para> + + <para>When forwarding to the kernel log buffer (kmsg), make sure to select a suitably large size for + the log buffer, and ensure the kernel's rate-limiting applied to userspace processes is turned + off. Specifically, add <literal>log_buf_len=8M</literal> and <literal>printk.devkmsg=on</literal> (or + similar) to the kernel command line.</para></listitem> </varlistentry> <varlistentry> |