Debian 8设置开机启动命令行界面及解除root用户登陆限制

CLI:command Line Interface，命令行界面，现在的Linux发行版默认登陆界面几乎都是默认为GUI界面，如果按照旧版本的修改inittab文件，在一些比较新的版本是没有这个文件的(Linux的启动服务机制发生改变)

debian8修改默认启动界面：修改启动程序grub配置文件实现

->打开grup配置文件：/etc/default/grub
->修改GRUB_CMDLINE_LINUX=”” 为GRUB_CMDLINE_LINUX=”text”
->更新grub:update-grub
->更新系统服务管理器配置：systemctl set-default multi-user.target
->重启：init 6(效果)

修改后的grub配置文件：

# If you change this file, run ‘update-grub’ afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n ‘Simple configuration’

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=lsb_release -i -s 2> /dev/null || echo Debian
GRUB_CMDLINE_LINUX_DEFAULT=”quiet”
GRUB_CMDLINE_LINUX=”text”

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD …)
#GRUB_BADRAM=”0x01234567,0xfefefefe,0x89abcdef,0xefefefef”

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo’
#GRUB_GFXMODE=640x480

# Uncomment if you don’t want GRUB to pass “root=UUID=xxx” parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY=”true”

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE=”480 440 1”

解除debian root用户登陆限制

->打开gdm配置文件：/etc/gdm3/deamon.conf
->配置安全设置：[security] 下一行添加“AllowRoot = ture”
->去除gdm登陆用户名检测：打开文件/etc/pam.d/gdm-autologin，并其相关配置信息删除或注释掉：auth required pam_succeed_if.so user != root quiet_success

修改后的gdm-autologin文件：

#%PAM-1.0
auth requisite pam_nologin.so
#auth required pam_succeed_if.so user != root quiet_success
auth required pam_permit.so
@include common-account
# SELinux needs to be the first session rule. This ensures that any
# lingering context has been cleared. Without this it is possible
# that a module could execute code in the wrong domain.
session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so close
session required pam_loginuid.so
# SELinux needs to intervene at login time to ensure that the process
# starts in the proper default security context. Only sessions which are
# intended to run in the user’s context should be run after this.
session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so open
session optional pam_keyinit.so force revoke
session required pam_limits.so
session required pam_env.so readenv=1
session required pam_env.so readenv=1 envfile=/etc/default/locale
@include common-session
@include common-password