Log service management

/root/install.log: The software package installed in the system and its version information are stored
/root/install.log.syslog: The event records left during the installation process are stored
/root/anaconda-ks.cfg: With Kickstart with Set the file format to record the option information set during installation

Common log files

Log files	explain
/var/log/cron	Logs related to system timing tasks are recorded .
/var/1og/cups/	Log printing information
/var/log/dmesg	It records the information of kernel self-test when the system is powered on . You can also use Amesg Command to view kernel self test information directly .
/var/log/btmp	Log error log . This file is binary , Not directly vi see , To use lastb Command view
/var/log/lastlog	Log the last login time of all users in the system . Not directly vi, And you want to use lastlog Command view .
/var/ log/mailog	Record mail information . A log of important information about a system . This log file will record Linux System size
/var/1og/message	Most important information , If there is a problem with the system , The first thing to check is this log file . Record verification and authorization information ,) Any program involving accounts and passwords will be recorded .
/var/1og/secure	For example, system login ,ssh The login ,su Switching users ,sudo to grant authorization , Even adding users and changing user passwords will be recorded in this log file . Log in all users permanently 、 Cancellation information , Simultaneously record the start-up of the system 、 restart 、
/var/1og/wtmp	Shutdown event . This file is also a binary , Not directly vi, It needs to be used last Order to see . Record the information of the currently logged in user . This file will follow the user's login and notes
/var/run/utmp	And constantly changing , Record only the information of the currently logged in user . Also, this file cannot be directly vi, And you want to use w,who, users etc. Order to inquire .

In addition to the system default log , use RPM The system service installed in mode will also log in by default /var/log/ Directory ( The service log of the source package installation is in the specified directory of the source package ). But these logs are not written by rsyslogd Services to record and manage , Instead, each service uses its own log management document to record its own logs .

Log files	explain
/var/log/ httpd/	RPM Packages installed apache Default log directory for services
/var/1og/mail/	RPM Additional log directory for package installed mail service
/var/ log/ samba/	RPM Packages installed samba Under the log directory of the service
/var/log/sssd/	Daemons security service directory

rsyslog

• rsyslogd New features

be based on TCP Network protocol transport log information ;
More secure network transmission mode ;
A timely analysis framework with log messages ;
Background database ;
Simple logic judgment can be written in the configuration file
And syslog with Set file compatible .

• The basic log format consists of the following four columns :
  1、 Time of occurrence ;
  2、 Host name of the server where the event occurred ;
  3、 The name of the service or program that generated the event ;
  4、 Details of the incident .

Log type	explain
auth	pam Generated log
suthpriv	ssh,ftp Verification information of login information
cron	Time task related
kern	kernel
lpr	Print
mail	mail
mark（syslog）-rlog	Information within the service , Time signs
news	Newsgroups
user	Information generated by the user program
uucp	unix to unix copy,unix Communication between hosts
local 1～7	Custom log device

The level of logging	explain
debug	Having tonal information , Log information is the most
info	General information log , The most commonly used
notice	The most important common condition of information
warning	Warning level
err	error level , Information that prevents a function or module from working properly
crit	Severity level , Information that prevents the entire system or software from working properly
alert	Information that needs to be changed immediately
emerg	Kernel crash and other serious information
none	Nothing is recorded