1, centos6 start management
1.1 significance of operation level
1.2 view operation level
[root@localhost log]# runlevel
3 5 //It means 5 at present, 3 before. If it's N, it means direct power on to enter 5
1.3. Set the default startup operation level
[root@localhost log]# vim /etc/inittab
2, Start the boot program grub
grub is the boot program of the system after power on. It provides the menu of which system to enter when power on.
2.1 grub configuration file
[root@localhost /]# vi /boot/grub/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/sda2
# initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0 //Start the first system by default
timeout=5 //Wait for five seconds.
splashimage=(hd0,0)/grub/splash.xpm.gz //Background image file
hiddenmenu //Hide startup selection screen similarwinMust pressf12To select a startup item
title CentOS 6 (2.6.32-642.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-642.el6.x86_64 //Loading kernel
ro root=UUID=d918b26f-fa87-4403-91c3-b27ae7c36640 rd_NO_LUKS
KEYBOARDTYPE=pc KEYTABLE=us rd_NO_MD crashkernel=auto LANG=zh_CN.UTF-8 rd_NO_LVM rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-642.el6.x86_64.img //Load simulation kernel
2.2 grub encryption
2.2.1. When linux starts, press e to enter grub editing mode, which is not safe
2.2.2. To set password for editing mode
[root@localhost ~]# grub-md5-crypt
Password: 123456
Retype password: 123456
$1$JnGVz/$bYexR/Ba/zYzg8IxDBhzX0.
[root@localhost ~]# vi /boot/grub/grub.conf
default=0
timeout=5
password --md5 $1$JnGVz/$bYexR/Ba/zYzg8IxDBhzX0
2.2.3. When linux starts again, you must press p and enter the password to enter e editing mode
