dmesg – Print or Control the kernel ring buffer
dmesg is used to examine or control the kernel ring buffer. The program helps users to print out their boot-up messages.
$ dmesg -- Print the kernel boot-up messages. $ dmesg > boot.log -- Redirect the output to a file. # dmesg -c -- Clear the ring buffer after printing. # dmesg -s4096 -- Set the kernel ring buffer size. # dmesg -n1 -- Set the level at which logging of messagesdone to the console.
- Action must be taken immediately
- Critical conditions
- Error conditions
- Warning conditions
- Normal but significant condition
- Debug-level messages
Read: man dmesg