Browsing articles tagged with "dmesg - Admins Goodies"
May 21, 2012
tom

How do I find out my CD ROM hardware specifics on FreeBSD?

I can usually use dmesg soon after bootup to display hardware info that my kernel loads. After my system has been up for a while however, dmesg no longer produces anything of value concerning hardware. How can I find out my hardware specifics, such as what kind of CD ROM drive I have, that is usually found by dmesg? Asked by EhevuTov For SATA and ATA drives atacontrol info ata# where # is the channel […]

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Mar 30, 2012
tom

Linux Centos with dmesg timestamp

I would like to read my Centos 5.x dmesg with timestamp, how do I do this? Asked by Elad Dotan dmesg reads the Kernel log ring buffer. It doesn’t do timestamps. What you should do is configure syslog to grab the kernel logs from that buffer and send them to a file (if it isn’t already set to do so). Note, default CentOS 5.x syslog config sends kernel logs to /var/log/messages, as I recall. If […]

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Mar 5, 2012
tom

How to convert ‘dmesg’ time format to ‘real’ time format

I have (for example) this log entry in dmesg output: [600711.395348] do_trap: 6 callbacks suppressed Is there a possibility to convert this ‘dmesg’ time to ‘real’ time to know, when this event happend? Asked by Jan Marek The time given in dmesg is in seconds since kernel startup. So, just add that many seconds to when the kernel started running (hint: uptime). Answered by Ignacio Vazquez-Abrams Check more discussion of this question. Bookmark on Delicious […]

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Aug 25, 2011
tom

What are these strange entries in dmesg?

Running Ubuntu Linux 9.04, and I see these odd log lines in dmesg: [ 18.673752] type=1505 audit(1240159967.221:2): operation=”profile_load” name=”/usr/share/gdm/guest-session/Xsession” name2=”default” pid=2197 [ 18.730952] type=1505 audit(1240159967.278:3): operation=”profile_load” name=”/sbin/dhclient-script” name2=”default” pid=2201 [ 18.731093] type=1505 audit(1240159967.278:4): operation=”profile_load” name=”/sbin/dhclient3″ name2=”default” pid=2201 [ 18.731141] type=1505 audit(1240159967.278:5): operation=”profile_load” name=”/usr/lib/NetworkManager/nm-dhcp-client.action” name2=”default” pid=2201 [ 18.731182] type=1505 audit(1240159967.278:6): operation=”profile_load” name=”/usr/lib/connman/scripts/dhclient-script” name2=”default” pid=2201 [ 18.871720] type=1505 audit(1240159967.417:7): operation=”profile_load” name=”/usr/lib/cups/backend/cups-pdf” name2=”default” pid=2206 [ 18.871913] type=1505 audit(1240159967.417:8): operation=”profile_load” name=”/usr/sbin/cupsd” name2=”default” pid=2206 [ 18.909533] type=1505 audit(1240159967.458:9): operation=”profile_load” name=”/usr/sbin/tcpdump” […]

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Aug 24, 2011
tom

Monitoring dmesg output

I find that when something goes wrong at a low level on one of my linux servers, I can see messages about it in the kernel ring buffer. These can be viewed from the command line using the dmesg command. I am wondering if there is an easy way to get my servers to email me whenever something is added to the kernel ring buffer? Right now I have a script that runs every hour, […]

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Aug 24, 2011
tom

Explain the output of dmesg

I am running a Debian system, and find the output of the dmesg command very helpful. Can somebody explain to me what information is output by the dmesg command? Is it a 1:1 correlation to the kern.* messages in syslog? Technically speaking dmesg prints the kernel ring buffer to standard output. I don’t know why they call it the ring buffer, but it’s basically a log buffer. All of the kernel boot messages get written […]

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Aug 18, 2011
tom

Is segfault signal always sent to application

My application usually crashes and prints stack to log if received segfault signal. But in some environment the ‘dmesg’ shows segfault messages related to my application, but application uptime is much older. Can segfault be suppressed and application doesn’t receive signal? Or what errors from dmesg can mean ? It is possible for an application or to ignore or do some special handling for the segmentation fault signal. The manual page for signal and related […]

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Aug 17, 2011
tom

How to add message that will be read with dmesg?

I am trying to write some custom messages in my dmesg output. I tried: logger “Hello” but this does not work. It exits without error, but no “Hello” appears int the output of: dmesg I am using a Fedora 9, and it seems that there is no syslogd/klogd daemon running. However, all my kernel messages are succesfully written in the dmesg buffer. Any idea? dmesg displays what is the kernel buffer, where is logger is […]

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Aug 15, 2011
tom

Dmesg and cpuinfo MHz differencies

I can see different values of CPU MHz here: cat /proc/cpuinfo model name : Intel(R) Xeon(R) CPU E3110 @ 3.00GHz stepping : 6 cpu MHz : 2000.000 Model say 3GHz and cpu MHz say 2GHz but dmesg | grep MHz say CPU0: Intel(R) Xeon(R) CPU E3110 @ 3.00GHz stepping 06 CPU1: Intel(R) Xeon(R) CPU E3110 @ 3.00GHz stepping 06 Why there is 2GHz shown? Your CPU and operating system are utilising Intel’s SpeedStep technology. This […]

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Aug 14, 2011
tom

why dmesg | grep Memory gives two different physical memory amounts?

I am monitoring physical memory in a server I administer, and my hardware provider told me they had increased physical memory size to 4Gb… However, using several tools (free -m; top; dmesg | grep Memory; grep MemTotal /proc/meminfo I discovered that I actually have 3Gb, not 4… But, my doubt comes from the fact that dmesg | grem Memory tells me I have 3103396k/4194304k available The first number is effectively 3Gb, but the second one, […]

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