DMESG Display Boot Information
Kernel will store the boot information in the ring buffer, if the boot time is too late to see, you can use the Dmeg view.
Path/VAR/LOG/DMESG
Common parameters:
-C After displaying the information, clear the contents of the ring buffer
-s< buffer size > Preset value is 8196, just equal to ring buffer size
-N Set the level of logging information
Instance:
1-Send a boot message
Man Dmesg wrote
The program helps users and print out their bootup messages. Instead of copying the messages by hand, the user need only:
DMESG > Boot.messages
and Mail the boot.messages file to whoever can debug their problem.
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[ email protected] ~]#mail-s "boot log of Linux server mysql01-new" [email protected]
2-Browse DMESG output information
Uname-a Viewing system version information
DMESG |less
Less/var/log/dmesg
Tail/var/log/dmesg
3-View serial information, network card information
grep ttys*/VAR/LOG/DMESG
Or: Dmes |grep ttys*
DMESG |grep-n ' em1 '
4-Print and clear the kernel information buffer
Dmesg-c
DMESG Display Boot Information command