Simple Linux Command Line notes: dmesg

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Display kernel messages

Dmesg [Options]

 

Dmesg can be used to display messages stored in the kernel ring buffer.

When the system starts, the kernel fills its ring buffer with messages initialized by hardware and modules. Messages in the kernel ring buffer are often used to diagnose system problems.

Option

-C kernel ring buffer after running dmesg

 

Example Dmesg>

[Root @ localhost ~] # Dmesg> Message [root @ localhost ~] # Head - 4 Message initializing cgroup subsys cpusetinitializing cgroup subsys cpulinux version  2.6 . 32 - 279 . El6.i686 (mockbuild@c6b9.bsys.dev.centos.org )( Gcc Version 4.4 . 6   20120305 (Red Hat 4.4 . 6 - 4 ) (GCC ))# 1 SMP Fri Jun22   10 : 59 : 55 UTC 2012  Kernel supported CPUs: 

Redirects system startup to a file

Dmesg | grep

[Root @ localhost ~] # Dmesg | Grep  Eth0e1000  0000 : 00 : 03.0 : Eth0: (pCI: 33 MHz: 32 -Bit)08 : 00 : 27 : 14 : 99  : A3e1000  0000 : 00 : 03.0 : Eth0: Intel (r) Pro/ 1000  Network connectione1000: eth0 Nic link is up  1000  Mbps full duplex, flow control: rx8021q: Adding VLAN  0 To HW filter on device eth0eth0: No IPv6 routers present 

Filter information in dmesg