[libvirt] [PATCH 5/5] Update logging documentation

Try to include a little more description about the corner cases, things someone might get hung up on on. --- docs/logging.html.in | 22 ++++++++++++++++++++-- 1 files changed, 20 insertions(+), 2 deletions(-) diff --git a/docs/logging.html.in b/docs/logging.html.in index fcd100f..1f3085d 100644 --- a/docs/logging.html.in +++ b/docs/logging.html.in @@ -44,6 +44,10 @@ <li>LIBVIRT_LOG_FILTERS: allow to define logging filters</li> <li>LIBVIRT_LOG_OUTPUTS: allow to define logging outputs</li> </ul> + <p>Note that, for example, setting LIBVIRT_DEBUG= is the same as unset. If + you specify an invalid value, it will be ignored with a warning. If you + have an error in a filter or output string, some of the settings may be + applied up to the point at which libvirt encountered the error.</p> <p>Similary the daemon logging behaviour can be tuned using 3 config variables, stored in the configuration file: <ul> @@ -57,7 +61,17 @@ <li>log_filters: allow to define logging filters</li> <li>log_outputs: allow to define logging outputs</li> </ul> - <p>In both case the syntax for filters and outputs is similar.</p> + <p>When starting the libvirt daemon, any logging environment variable + settings will override settings in the config file. Command line options + take precedence over all. If no outputs are defined for libvirtd, it + defaults to logging to syslog when it is running as a daemon, or to + stderr when it is running in the foreground.</p> + <p>Libvirtd does not reload its logging configuration when issued a SIGHUP. + If you want to reload the configuration, you must do a <code>service + libvirtd reload</code> or manually stop and restart the daemon + yourself.</p> + <p>The syntax for filters and outputs is the same for both types of + variables.</p> <p>The format for a filter is:</p> <pre>x:name</pre> <p>where <code>name</code> is a match string e.g. <code>remote</code> or @@ -69,10 +83,14 @@ <li>3: WARNING</li> <li>4: ERROR</li> </ul> - <p>Multiple filter can be defined in a single string, they just need to be + <p>Multiple filters can be defined in a single string, they just need to be separated by spaces, e.g: <code>"3:remote 4:event"</code> to only get warning or errors from the remote layer and only errors from the event layer.<p> + <p>If you specify a log priority in a filter that is below the default log + priority level, messages that match that filter will still be logged, + while others will not. In order to see those messages, you must also have + an output defined that includes the priority level of your filter.</p> <p>The format for an output can be one of those 3 forms:</p> <ul> <li><code>x:stderr</code> output goes to stderr</li>