mirror of
https://git.proxmox.com/git/systemd
synced 2025-05-29 10:01:12 +00:00
106 lines
11 KiB
HTML
106 lines
11 KiB
HTML
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>systemd-journald.service</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><style>
|
|
a.headerlink {
|
|
color: #c60f0f;
|
|
font-size: 0.8em;
|
|
padding: 0 4px 0 4px;
|
|
text-decoration: none;
|
|
visibility: hidden;
|
|
}
|
|
|
|
a.headerlink:hover {
|
|
background-color: #c60f0f;
|
|
color: white;
|
|
}
|
|
|
|
h1:hover > a.headerlink, h2:hover > a.headerlink, h3:hover > a.headerlink, dt:hover > a.headerlink {
|
|
visibility: visible;
|
|
}
|
|
</style><a href="index.html">Index </a>·
|
|
<a href="systemd.directives.html">Directives </a>·
|
|
<a href="../python-systemd/index.html">Python </a>·
|
|
<a href="../libudev/index.html">libudev </a>·
|
|
<a href="../libudev/index.html">gudev </a><span style="float:right">systemd 219</span><hr><div class="refentry"><a name="systemd-journald.service"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>systemd-journald.service, systemd-journald.socket, systemd-journald-dev-log.socket, systemd-journald — Journal service</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><p><code class="filename">systemd-journald.service</code></p><p><code class="filename">systemd-journald.socket</code></p><p><code class="filename">systemd-journald-dev-log.socket</code></p><p><code class="filename">/usr/lib/systemd/systemd-journald</code></p></div><div class="refsect1"><a name="idm140020573047136"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p><code class="filename">systemd-journald</code> is a system service
|
|
that collects and stores logging data. It creates and maintains
|
|
structured, indexed journals based on logging information that is
|
|
received from a variety of sources:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Kernel log messages, via kmsg</p></li><li class="listitem"><p>Simple system log messages, via the libc
|
|
<a href="http://man7.org/linux/man-pages/man3/syslog.3.html"><span class="citerefentry"><span class="refentrytitle">syslog</span>(3)</span></a>
|
|
call</p></li><li class="listitem"><p>Structured system log messages via the native
|
|
Journal API, see
|
|
<a href="http://man7.org/linux/man-pages/man4/sd_journal_print.4.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_print</span>(4)</span></a></p></li><li class="listitem"><p>Standard output and standard error of system
|
|
services</p></li><li class="listitem"><p>Audit records, via the audit
|
|
subsystem</p></li></ul></div><p>The daemon will implicitly collect numerous metadata fields
|
|
for each log messages in a secure and unfakeable way. See
|
|
<a href="systemd.journal-fields.html"><span class="citerefentry"><span class="refentrytitle">systemd.journal-fields</span>(7)</span></a>
|
|
for more information about the collected metadata.
|
|
</p><p>Log data collected by the journal is primarily text-based
|
|
but can also include binary data where necessary. All objects
|
|
stored in the journal can be up to 2^64-1 bytes in size.</p><p>By default, the journal stores log data in
|
|
<code class="filename">/run/log/journal/</code>. Since
|
|
<code class="filename">/run/</code> is volatile, log data is lost at
|
|
reboot. To make the data persistent, it is sufficient to create
|
|
<code class="filename">/var/log/journal/</code> where
|
|
<code class="filename">systemd-journald</code> will then store the
|
|
data.</p><p><code class="filename">systemd-journald</code> will forward all
|
|
received log messages to the
|
|
<code class="constant">AF_UNIX</code>/<code class="constant">SOCK_DGRAM</code>
|
|
socket <code class="filename">/run/systemd/journal/syslog</code>, if it
|
|
exists, which may be used by Unix syslog daemons to process the
|
|
data further.</p><p>See
|
|
<a href="journald.conf.html"><span class="citerefentry"><span class="refentrytitle">journald.conf</span>(5)</span></a>
|
|
for information about the configuration of this service.</p></div><div class="refsect1"><a name="idm140020576933776"></a><h2 id="Signals">Signals<a class="headerlink" title="Permalink to this headline" href="#Signals">¶</a></h2><div class="variablelist"><dl class="variablelist"><dt id="SIGUSR1"><span class="term">SIGUSR1</span><a class="headerlink" title="Permalink to this term" href="#SIGUSR1">¶</a></dt><dd><p>Request that journal data from
|
|
<code class="filename">/run/</code> is flushed to
|
|
<code class="filename">/var/</code> in order to make it persistent (if
|
|
this is enabled). This must be used after
|
|
<code class="filename">/var/</code> is mounted, as otherwise log data
|
|
from <code class="filename">/run</code> is never flushed to
|
|
<code class="filename">/var</code> regardless of the
|
|
configuration.</p></dd><dt id="SIGUSR2"><span class="term">SIGUSR2</span><a class="headerlink" title="Permalink to this term" href="#SIGUSR2">¶</a></dt><dd><p>Request immediate rotation of the journal
|
|
files.</p></dd></dl></div></div><div class="refsect1"><a name="idm140020576926240"></a><h2 id="Kernel Command Line">Kernel Command Line<a class="headerlink" title="Permalink to this headline" href="#Kernel%20Command%20Line">¶</a></h2><p>A few configuration parameters from
|
|
<code class="filename">journald.conf</code> may be overridden on the kernel
|
|
command line:</p><div class="variablelist"><dl class="variablelist"><dt id="systemd.journald.forward_to_syslog="><span class="term"><code class="varname">systemd.journald.forward_to_syslog=</code>, </span><span class="term"><code class="varname">systemd.journald.forward_to_kmsg=</code>, </span><span class="term"><code class="varname">systemd.journald.forward_to_console=</code>, </span><span class="term"><code class="varname">systemd.journald.forward_to_wall=</code></span><a class="headerlink" title="Permalink to this term" href="#systemd.journald.forward_to_syslog=">¶</a></dt><dd><p>Enables/disables forwarding of collected log
|
|
messages to syslog, the kernel log buffer, the system console
|
|
or wall.
|
|
</p><p>See
|
|
<a href="journald.conf.html"><span class="citerefentry"><span class="refentrytitle">journald.conf</span>(5)</span></a>
|
|
for information about these settings.</p></dd></dl></div></div><div class="refsect1"><a name="idm140020576912112"></a><h2 id="Access Control">Access Control<a class="headerlink" title="Permalink to this headline" href="#Access%20Control">¶</a></h2><p>Journal files are, by default, owned and readable by the
|
|
"<code class="literal">systemd-journal</code>" system group but are not
|
|
writable. Adding a user to this group thus enables her/him to read
|
|
the journal files.</p><p>By default, each logged in user will get her/his own set of
|
|
journal files in <code class="filename">/var/log/journal/</code>. These
|
|
files will not be owned by the user, however, in order to avoid
|
|
that the user can write to them directly. Instead, file system
|
|
ACLs are used to ensure the user gets read access only.</p><p>Additional users and groups may be granted access to journal
|
|
files via file system access control lists (ACL). Distributions
|
|
and administrators may choose to grant read access to all members
|
|
of the "<code class="literal">wheel</code>" and "<code class="literal">adm</code>" system
|
|
groups with a command such as the following:</p><pre class="programlisting"># setfacl -Rnm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/</pre><p>Note that this command will update the ACLs both for
|
|
existing journal files and for future journal files created in the
|
|
<code class="filename">/var/log/journal/</code> directory.</p></div><div class="refsect1"><a name="idm140020576904928"></a><h2 id="Files">Files<a class="headerlink" title="Permalink to this headline" href="#Files">¶</a></h2><div class="variablelist"><dl class="variablelist"><dt id="/etc/systemd/journald.conf"><span class="term"><code class="filename">/etc/systemd/journald.conf</code></span><a class="headerlink" title="Permalink to this term" href="#/etc/systemd/journald.conf">¶</a></dt><dd><p>Configure
|
|
<span class="command"><strong>systemd-journald</strong></span>
|
|
behaviour. See
|
|
<a href="journald.conf.html"><span class="citerefentry"><span class="refentrytitle">journald.conf</span>(5)</span></a>.
|
|
</p></dd><dt id="/run/log/journal/machine-id/*.journal"><span class="term"><code class="filename">/run/log/journal/<em class="replaceable"><code>machine-id</code></em>/*.journal</code>, </span><span class="term"><code class="filename">/run/log/journal/<em class="replaceable"><code>machine-id</code></em>/*.journal~</code>, </span><span class="term"><code class="filename">/var/log/journal/<em class="replaceable"><code>machine-id</code></em>/*.journal</code>, </span><span class="term"><code class="filename">/var/log/journal/<em class="replaceable"><code>machine-id</code></em>/*.journal~</code></span><a class="headerlink" title="Permalink to this term" href="#/run/log/journal/machine-id/*.journal">¶</a></dt><dd><p><span class="command"><strong>systemd-journald</strong></span> writes
|
|
entries to files in
|
|
<code class="filename">/run/log/journal/<em class="replaceable"><code>machine-id</code></em>/</code>
|
|
or
|
|
<code class="filename">/var/log/journal/<em class="replaceable"><code>machine-id</code></em>/</code>
|
|
with the "<code class="literal">.journal</code>" suffix. If the daemon is
|
|
stopped uncleanly, or if the files are found to be corrupted,
|
|
they are renamed using the "<code class="literal">.journal~</code>"
|
|
suffix, and <span class="command"><strong>systemd-journald</strong></span> starts writing
|
|
to a new file. <code class="filename">/run</code> is used when
|
|
<code class="filename">/var/log/journal</code> is not available, or
|
|
when <code class="option">Storage=volatile</code> is set in the
|
|
<a href="journald.conf.html"><span class="citerefentry"><span class="refentrytitle">journald.conf</span>(5)</span></a>
|
|
configuration file. </p></dd></dl></div></div><div class="refsect1"><a name="idm140020571975440"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
|
|
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
|
|
<a href="journalctl.html"><span class="citerefentry"><span class="refentrytitle">journalctl</span>(1)</span></a>,
|
|
<a href="journald.conf.html"><span class="citerefentry"><span class="refentrytitle">journald.conf</span>(5)</span></a>,
|
|
<a href="systemd.journal-fields.html"><span class="citerefentry"><span class="refentrytitle">systemd.journal-fields</span>(7)</span></a>,
|
|
<a href="sd-journal.html"><span class="citerefentry"><span class="refentrytitle">sd-journal</span>(3)</span></a>,
|
|
<a href="systemd-coredump.html"><span class="citerefentry"><span class="refentrytitle">systemd-coredump</span>(8)</span></a>,
|
|
<a href="setfacl.html"><span class="citerefentry"><span class="refentrytitle">setfacl</span>(1)</span></a>,
|
|
<a href="http://man7.org/linux/man-pages/man4/sd_journal_print.4.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_print</span>(4)</span></a>,
|
|
<span class="command"><strong>pydoc systemd.journal</strong></span>.
|
|
</p></div></div></body></html>
|