dmesg > boot.messages

Useful: print out their bootup messages.

Actual: print or control the kernel ring buffer

-nlevel

set the level at which logging of messages is done to the
console.  For example, -n 1 prevents all messages, expect
panic messages, from appearing on the console.  All levels of
messages are still written to /proc/kmsg, so syslogd(8) can
still be used to control exactly where kernel messages appear.
When the -n option is used, dmesg will not print or clear the
kernel ring buffer.