ubuntu20.04 默认是没有开启root登录的

ubuntu20.04 默认是没有开启root登录的，这在我们桌面操作和配置文件的时候很不方便，于是这里教大家用root直接登录桌面，这样操作系统起来非常方便

一：设置root用户密码

在桌面上右键鼠标选择Open in Terminal打开终端模拟器
执行sudo passwd root
然后输入设置的密码，输入两次，这样就完成了设置root用户密码了
切换到root账号su root

二：修改配置文件

2.1：修改50-ubuntu.conf

备份：

root@arbor-virtual-machine:/usr/share/lightdm/lightdm.conf.d# cp 50-ubuntu.conf 50-ubuntu.conf.bak
root@arbor-virtual-machine:/usr/share/lightdm/lightdm.conf.d# ls
50-ubuntu.conf  50-ubuntu.conf.bak
root@arbor-virtual-machine:/usr/share/lightdm/lightdm.conf.d# 

执行:

sudo vim /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf

把配置改为如下所示

[Seat:*]
user-session=ubuntu
greeter-show-manual-login=true
all-guest=false #这个可以 不用配置

2.2：修改gdm-autologin

备份

cd /etc/pam.d
cp gdm-autologin gdm-autologin.bak

执行

sudo vim /etc/pam.d/gdm-autologin

注释掉auth required pam_succeed_if.so user != root quiet_success这一行(在第三行左右)

#%PAM-1.0
auth    requisite       pam_nologin.so
#auth   required        pam_succeed_if.so user != root quiet_success
auth    optional        pam_gdm.so
auth    optional        pam_gnome_keyring.so
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 user_readenv=1 envfile=/etc/default/locale
@include common-session
session optional        pam_gnome_keyring.so auto_start
@include common-password

2.3：修改gdm-password

执行sudo vim /etc/pam.d/gdm-password注释掉 auth required pam_succeed_if.so user != root quiet_success这一行(第三行左右)
备份

cp gdm-password gdm-password.bak

#%PAM-1.0
auth    requisite       pam_nologin.so
#auth   required        pam_succeed_if.so user != root quiet_success
@include common-auth
auth    optional        pam_gnome_keyring.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.
# pam_selinux.so changes the SELinux context of the used TTY and configures
# SELinux in order to transition to the user context with the next execve()
# call.
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 user_readenv=1 envfile=/etc/default/locale
@include common-session
session optional        pam_gnome_keyring.so auto_start
@include common-password

2.4：修改/proroot/.file文件

备份

root@arbor-virtual-machine:~# cp .profile .profile.bak

执行sudo vim /root/.profile修改配置文件如下

# ~/.profile: executed by Bourne-compatible login shells.
 
if [ "$BASH" ]; then
 if [ -f ~/.bashrc ]; then
  . ~/.bashrc
 fi
fi
tty -s && mesg n || true
mesg n || true

三：重启系统使其生效

重启后注销原来用户
登录选择未列出

在这里插入图片描述

登录root用户