15.4. syslog, klogctl - read and/or clear kernel message ring buffer; set console_loglevel

enables logging from remote machines

# vim /etc/sysconfig/syslog

#SYSLOGD_OPTIONS="-m 0"
SYSLOGD_OPTIONS="-r -m 0"
			

# /etc/init.d/syslog restart
Shutting down kernel logger:                               [  OK  ]
Shutting down system logger:                               [  OK  ]
Starting system logger:                                    [  OK  ]
Starting kernel logger:                                    [  OK  ]
			

*.*			@172.16.0.9
			

所有日志将被重定向到172.16.0.9

[root@dev1 test]# service syslog restart
Shutting down kernel logger:                               [  OK  ]
Shutting down system logger:                               [  OK  ]
Starting system logger:                                    [  OK  ]
Starting kernel logger:                                    [  OK  ]
[root@dev1 test]#
			

日志的级别

emerg 系统已经不可用，级别为紧急
alert 警报，需要立即处理和解决
crit 既将发生，得需要预防。事件就要发生
warnig 警告
err 错误信息，普通的错误信息
notice 提醒信息，很重要的信息
info 通知信息，属于一般信息
debug 这是调试类信息
			

#vi /etc/syslog.conf

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none;cron.none;local1.none;local3.none /var/log/messages

#my log
local3.* /var/log/my.log
			

# service syslog restart
Shutting down kernel logger:                               [  OK  ]
Shutting down system logger:                               [  OK  ]
Starting system logger:                                    [  OK  ]
Starting kernel logger:                                    [  OK  ]
			

ping 192.168.0.1 | logger -it logger_test -p local3.notice
			

# cat /var/log/my.log
Jan 12 18:06:03 dev1 logger_test[10991]: PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
Jan 12 18:06:03 dev1 logger_test[10991]: 64 bytes from 192.168.0.1: icmp_seq=1 ttl=64 time=0.746 ms
Jan 12 18:06:04 dev1 logger_test[10991]: 64 bytes from 192.168.0.1: icmp_seq=2 ttl=64 time=0.713 ms
Jan 12 18:06:05 dev1 logger_test[10991]: 64 bytes from 192.168.0.1: icmp_seq=3 ttl=64 time=0.924 ms
Jan 12 18:06:06 dev1 logger_test[10991]: 64 bytes from 192.168.0.1: icmp_seq=4 ttl=64 time=0.819 ms
Jan 12 18:06:08 dev1 logger_test[10991]: 64 bytes from 192.168.0.1: icmp_seq=5 ttl=64 time=0.667 ms
Jan 12 18:06:09 dev1 logger_test[10991]: 64 bytes from 192.168.0.1: icmp_seq=6 ttl=64 time=0.626 ms
Jan 12 18:06:10 dev1 logger_test[10991]: 64 bytes from 192.168.0.1: icmp_seq=7 ttl=64 time=0.665 ms