Q. I am new to Linux and I would like to know where are the log files located under Debian or Cento OS Linux server? How do I open or view log files?
A. Almost all logfiles are located under /var/log directory (and subdirectory). You can change to this directory using cd command but you need to be the root user. You can use less, more, cat or tail command to see the logs.
Go to /var/logs directory:# cd /var/logsView common log file /var/log/messages using any one of the following command:# tail -f /var/log/messagesOutput:
# less /var/log/messages
# more -f /var/log/messages
# vi /var/log/messages
Jul 17 22:04:25 router dnsprobe[276]: dns query failed Jul 17 22:04:29 router last message repeated 2 times Jul 17 22:04:29 router dnsprobe[276]: Primary DNS server Is Down... Switching To Secondary DNS server Jul 17 22:05:08 router dnsprobe[276]: Switching Back To Primary DNS server Jul 17 22:26:11 debian -- MARK -- Jul 17 22:46:11 debian -- MARK -- Jul 17 22:47:36 router -- MARK -- Jul 17 22:47:36 router dnsprobe[276]: dns query failed Jul 17 22:47:38 debian kernel: rtc: lost some interrupts at 1024Hz. Jun 17 22:47:39 debian kernel: IN=eth0 OUT= MAC=00:0f:ea:91:04:07:00:08:5c:00:00:01:08:00 SRC=61.4.218.24 DST=192.168.1.100 LEN=60 TOS=0x00 PREC=0x00 TTL=46 ID=21599 DF PROTO=TCP SPT=59297 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0
Common Linux log files name and usage
- /var/log/message: General message and system related stuff
- /var/log/auth.log: Authenication logs
- /var/log/kern.log: Kernel logs
- /var/log/cron.log: Crond logs (cron job)
- /var/log/maillog: Mail server logs
- /var/log/qmail/ : Qmail log directory (more files inside this directory)
- /var/log/httpd/: Apache access and error logs directory
- /var/log/lighttpd: Lighttpd access and error logs directory
- /var/log/boot.log : System boot log
- /var/log/mysqld.log: MySQL database server log file
- /var/log/secure: Authentication log
- /var/log/utmp or /var/log/wtmp : Login records file
- /var/log/yum.log: Yum log files
In short /var/log is the location where you should find all Linux logs file. However some applications such as httpd have a directory within /var/log/ for their own log files. You can rotate log file using logrotate software and monitor logs files using logwatch software.
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{ 12 comments… read them below or add one }
Very informative. Helped me :) thumbs up
dear talent,
Can u help me how to redirect the /var/log/messages to email.
DNS server if any clients query log will stores /var/log/messages files i need to send those lof files in ip wise daily or weekly.
how shell i do it.
Dear Vivek,
I had an automatic reboot system in my server linux and I don´t find any evidence about the cause that could produce that.
Can you explain me where I have to looking for logs of error that guide me to find automatic reboot cause?.
Regards,
Gonzalo R.
where can i find the AT command logs. how to find out when the last time AT command run.
Thank you very much.
Chandra You can do this by opening a terminal and typing #cd /var/log/ and may view the files in the directory by typing #ls . You may view the log by typing #vi /var/log/messages .
I can see a lot of the following error in my system and I cannot understand what it means, can yu shed somelight on it
Feb 22 04:40:00 msuic3 msu6_6: ciMonitor 3 of 131 registered tasks Failed!
It’s a fruitful information…
Thanks a lot vivek
Hi,
I want classify logs and store it in a database. Into what categories can/should I classify them.
Thank you,
Sparrow
Hi there Linux users, I have bean trying to in stall Debian Lenny beta 2-i386 in a raid 0 con fig, on my p/c
the hard ware is all set up for raid 0, I am having difficulty with the configuration of the partitons, boot sector, file type, the “type of file allocation table” to install. I have bean trying to track down the
var/log, but I cant find that, the location was “http://192.2.2/var/log/partman_choose_partitiion_o.png
I have bean using pure dyne live CD to help me ,but I still was not able to look at the “/var/logs,
invariable I think I need expert help. thank you in advance
I have a basic account in linux of my intitue. How can i know all the login sessions done in my account ,their timing etc… an i also know any ftp or ssh done in my account?????
Just type
last
it will tell you when, what ip address, time in and out , and for how long