sorry to bother you but I've got a doubt about Unit 7 - Installing the New Kernel.
Is this correct:
dmesg -t -l alert > dmesg_current_alert
dmesg -t -l crit > dmesg_current_alert
It is correct. If all is well on your system, you will not see any alert, crit, emerg level messages on your system. The argument -l specifies the level and -t is for not printing the timestamps
When in doubt check dmesg -h for detailed information on the command options:
-l, --level restrict output to defined levels
-t, --notime don't show any timestamp with messages