Debian Kernel Error Log
Contents |
Introduction Target Audience System Logs Authorization Log Daemon Log Debug Log Kernel Log Kernel Ring Buffer System Log Application Logs Apache HTTP Server Logs CUPS Print System Logs Rootkit Hunter Log Samba SMB Server debian php error log Logs X11 Server Log Non-Human-Readable Logs Login Failures Log Last Logins Log debian apache error log Login Records Log System Logging Daemon (syslogd) Configuration of syslogd Echoing Messages to syslogd With Logger Log Rotation Essential Commands debian mysql error log Getting Started Editing Files Viewing Files Viewing the Beginning of Files Viewing the End of Files Watching a Changing File Searching Files Resources Local System Resources WWW Resources Introduction One of
Debian Apache2 Error Log
the things which makes GNU/Linux a great operating system is that virtually anything and everything happening on and to the system may be logged in some manner. This information is invaluable for using the system in an informed manner, and should be one of the first resources you use to trouble-shoot system and application issues. The logs can tell you almost anything you need linux kernel error log to know, as long as you have an idea where to look first. Your Ubuntu system provides vital information using various system log files. These log files are typically plain ASCII text in a standard log file format, and most of them sit in the traditional system log subdirectory /var/log. Many are generated by the system log daemon, syslogd on behalf of the system and certain applications, while some applications generate their own logs by writing directly to files in /var/log. This guide talks about how to read and use several of these system log files, how to use and configure the system logging daemon, syslogd, and how log rotation works. See the Resources section for additional information. Target Audience This guide will be simple enough to use if you have any experience using the console and editing text files using a text editor. See the end of this document for some essential commands that may help you find your way around these files if you're relatively new to the command line. System Logs System logs deal primarily with the functioning of the Ubuntu system, not necessarily with additional a
know where the log files are located, and what is contained in each and linux system log location every log file. When your systems are running smoothly, take some
Linux /var/log/messages
time to learn and understand the content of various log files, which will help you when there
Linux Log Files Explained
is a crisis and you have to look though the log files to identify the issue. /etc/rsyslog.conf controls what goes inside some of the log files. For example, https://help.ubuntu.com/community/LinuxLogFiles following is the entry in rsyslog.conf for /var/log/messages. $ grep "/var/log/messages" /etc/rsyslog.conf *.info;mail.none;authpriv.none;cron.none /var/log/messages In the above output, *.info indicates that all logs with type INFO will be logged. mail.none,authpriv.none,cron.none indicates that those error messages should not be logged into the /var/log/messages file. You can also specify *.none, which indicates that none of the log http://www.thegeekstuff.com/2011/08/linux-var-log-files messages will be logged. The following are the 20 different log files that are located under /var/log/ directory. Some of these log files are distribution specific. For example, you'll see dpkg.log on Debian based systems (for example, on Ubuntu). /var/log/messages - Contains global system messages, including the messages that are logged during system startup. There are several things that are logged in /var/log/messages including mail, cron, daemon, kern, auth, etc. /var/log/dmesg - Contains kernel ring buffer information. When the system boots up, it prints number of messages on the screen that displays information about the hardware devices that the kernel detects during boot process. These messages are available in kernel ring buffer and whenever the new message comes the old message gets overwritten. You can also view the content of this file using the dmesg command. /var/log/auth.log - Contains system authorization information, including user logins and authentication machinsm that were used. /var/log/boot.log - Contains information that are logged when the system boots /var/log/daemon.log -
communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company http://askubuntu.com/questions/104771/where-are-kernel-panic-logs Business Learn more about hiring developers or posting ads with us Ask Ubuntu Questions Tags http://unix.stackexchange.com/questions/35851/whats-the-difference-of-dmesg-output-and-var-log-messages Users Badges Unanswered Ask Question _ Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top Where are kernel panic logs? up vote 20 down error log vote favorite 8 I've got problem with Handbrake/ffmpeg. After ~5 minutes transcoding, the computer locks up. I'm fairly sure it's a kernel panic because caps-lock starts flashing. There are a few logical questions about what to do and some about specific bugs but I'm really after one thing: what happened right before everything died?! I've checked /var/log/kern.log and all I see around the time is me sticking in a DVD and then a few minutes later, kernel error log the system booting up. No errors, no panic notice. Is there any way to force panics to be logged? I'm fairly sure I can reproduce this (it's happened 100% of the times I've tried recently) so while I'd rather this "just worked", I'm happy enough to reboot a few times if it means I can find the cause of the panic. kernel log share|improve this question edited Jul 14 '14 at 9:52 asked Feb 16 '12 at 15:01 Oli♦ 172k55433644 Any specific message you get when transcoding? Might be useful in tracking down the solution ;) –Rinzwind Feb 16 '12 at 15:29 @Rinzwind Nope. Didn't show anything, just froze. –Oli♦ Feb 16 '12 at 15:33 Most likely an overheating problem. Transcoding drives the CPU hard, and if your cooling isn't 100% effective the CPU will go into emergency shutdown. I've seen this happen when the thermal paste was dried out on the CPU heatsink, for example. It also happened when the overclocking settings were messed up in the BIOS. Try using xsensors to monitor the CPU temperature just before the lockup. –Neil Mayhew Oct 20 '15 at 22:10 add a comment| 2 Answers 2 active oldest votes up vote 15 down vote accepted All your system logs in Ubuntu are handled by rsyslog which keeps its configuration in /
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Unix & Linux Questions Tags Users Badges Unanswered Ask Question _ Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. Join them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top What's the difference of dmesg output and /var/log/messages? up vote 28 down vote favorite 8 AFAIK dmesg shows information about kernel and kernel modules, and /var/log/messages also shows information produced by kernel and modules. So what's the difference? Does /var/log/messages ⊂ output of dmesg? More Info that may be helpful: - There is a kernel ring buffer, which I think is the very and only place to store kernel log data. - Article "Kernel logging: APIs and implementation" on IBM DeveloperWorks described APIs and the bird-view picture. kernel logs share|improve this question asked Apr 6 '12 at 4:12 xanpeng 1,23751518 add a comment| 4 Answers 4 active oldest votes up vote 27 down vote accepted dmesg prints the contents of the ring buffer. This information is also sent in real time to syslogd or klogd, when they are running, and ends up in /var/log/messages; when dmesg is most useful is in capturing boot-time messages from before syslogd and/or klogd started, so that they will be properly logged. share|improve this answer answered Apr 6 '12 at 4:20 geekosaur 16.7k24247 1 So /var/log/messages and dmesg will show the same logs (in different format) after syslogd and/or klogd started? –xanpeng Apr 6 '12 at 4:56 4 After klogd is running, dmesg will show only the most recent kernel messages (because the ring buffer is a fixed size and so can only hold so much), without timestamps or other information, while /var/log/messages will retain logs according to how logrotate is