52 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
		
		
			
		
	
	
			52 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
|   | <chapter xmlns="http://docbook.org/ns/docbook" | |||
|  |         xmlns:xlink="http://www.w3.org/1999/xlink" | |||
|  |         xmlns:xi="http://www.w3.org/2001/XInclude" | |||
|  |         version="5.0" | |||
|  |         xml:id="sec-logging"> | |||
|  | 
 | |||
|  | <title>Logging</title> | |||
|  | 
 | |||
|  | <para>System-wide logging is provided by systemd’s | |||
|  | <emphasis>journal</emphasis>, which subsumes traditional logging | |||
|  | daemons such as syslogd and klogd.  Log entries are kept in binary | |||
|  | files in <filename>/var/log/journal/</filename>.  The command | |||
|  | <literal>journalctl</literal> allows you to see the contents of the | |||
|  | journal.  For example, | |||
|  | 
 | |||
|  | <screen> | |||
|  | $ journalctl -b | |||
|  | </screen> | |||
|  | 
 | |||
|  | shows all journal entries since the last reboot.  (The output of | |||
|  | <command>journalctl</command> is piped into <command>less</command> by | |||
|  | default.)  You can use various options and match operators to restrict | |||
|  | output to messages of interest.  For instance, to get all messages | |||
|  | from PostgreSQL: | |||
|  | 
 | |||
|  | <screen> | |||
|  | $ journalctl -u postgresql.service | |||
|  | -- Logs begin at Mon, 2013-01-07 13:28:01 CET, end at Tue, 2013-01-08 01:09:57 CET. -- | |||
|  | ... | |||
|  | Jan 07 15:44:14 hagbard postgres[2681]: [2-1] LOG:  database system is shut down | |||
|  | -- Reboot -- | |||
|  | Jan 07 15:45:10 hagbard postgres[2532]: [1-1] LOG:  database system was shut down at 2013-01-07 15:44:14 CET | |||
|  | Jan 07 15:45:13 hagbard postgres[2500]: [1-1] LOG:  database system is ready to accept connections | |||
|  | </screen> | |||
|  | 
 | |||
|  | Or to get all messages since the last reboot that have at least a | |||
|  | “critical” severity level: | |||
|  | 
 | |||
|  | <screen> | |||
|  | $ journalctl -b -p crit | |||
|  | Dec 17 21:08:06 mandark sudo[3673]: pam_unix(sudo:auth): auth could not identify password for [alice] | |||
|  | Dec 29 01:30:22 mandark kernel[6131]: [1053513.909444] CPU6: Core temperature above threshold, cpu clock throttled (total events = 1) | |||
|  | </screen> | |||
|  | 
 | |||
|  | </para> | |||
|  | 
 | |||
|  | <para>The system journal is readable by root and by users in the | |||
|  | <literal>wheel</literal> and <literal>systemd-journal</literal> | |||
|  | groups.  All users have a private journal that can be read using | |||
|  | <command>journalctl</command>.</para> | |||
|  | 
 | |||
|  | </chapter> |