Monday, October 5, 2009

dmesg: Command for Reviewing Boot Messages

The dmesg command displays the system messages contained in the kernel ring buffer. If you want to see the boot messages immediately after booting your computer you can use dmesg

dmesg ("diagnostic message") is a command on Unix-like operating systems that prints the message buffer of the kernel. This buffer contains a lot of important messages from those output during boot, this can be used for diagnostic purpose.

Howto use

open a terminal and type the following

$ dmesg

see sample part
$ dmesg |more
[ 0.000000] BIOS EBDA/lowmem at: 0009fc00/0009fc00
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Linux version 2.6.28-11-generic (buildd@palmer) (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #42-Ubuntu SMP Fr
i Apr 17 01:57:59 UTC 2009 (Ubuntu 2.6.28-11.42-generic)
[ 0.000000] KERNEL supported cpus:
[ 0.000000] Intel GenuineIntel
[ 0.000000] AMD AuthenticAMD
[ 0.000000] NSC Geode by NSC
[ 0.000000] Cyrix CyrixInstead
[ 0.000000] Centaur CentaurHauls
[ 0.000000] Transmeta GenuineTMx86
[ 0.000000] Transmeta TransmetaCPU
[ 0.000000] UMC UMC UMC UMC
[ 0.000000] BIOS-provided physical RAM map:
[ 0.000000] BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
[ 0.000000] BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)