Ubuntu 20.04.2如何root登录

Ubuntu 20.04.2默认不能进行root登录

1、查看系统版本

liujiaxin01@liujiaxin01-virtual-machine:~/Desktop$ whoami
liujiaxin01
liujiaxin01@liujiaxin01-virtual-machine:~/Desktop$ cat /proc/version
Linux version 5.8.0-59-generic (buildd@lcy01-amd64-022) (gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #66~20.04.1-Ubuntu SMP Thu Jun 17 11:14:10 UTC 2021

2、测试使用root登录

3、修改50-ubuntu.conf配置文件

liujiaxin01@liujiaxin01-virtual-machine:~/Desktop$ sudo vim /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[sudo] password for liujiaxin01: ## 输入密码， 以下是修改后的内容，新增了3、4行
[Seat:*]                           
user-session=ubuntu
greeter-show-manual-login= true ## now line
all-guest=false # new line, not necessary

4、修改gdm-autologin配置文件

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(第三行左右)

liujiaxin01@liujiaxin01-virtual-machine:~/Desktop$ sudo vim /etc/pam.d/gdm-autologin
#%PAM-1.0
auth    requisite       pam_nologin.so
#auth   required        pam_succeed_if.so user != root quiet_success  // 注释掉这一行
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
…………

5、修改gdm-password配置文件

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)

liujiaxin01@liujiaxin01-virtual-machine:~/Desktop$ sudo vim /etc/pam.d/gdm-password
#%PAM-1.0
auth    requisite       pam_nologin.so
#auth   required        pam_succeed_if.so user != root quiet_success  ## 注释掉这一行
@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.
…………

6、修改/root/.profile文件

执行sudo vim /root/.profile修改配置文件如下：

liujiaxin01@liujiaxin01-virtual-machine:~/Desktop$ sudo vim /root/.profile
# ~/.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
#mesg n 2> /dev/null || true

7、重启系统

liujiaxin01@liujiaxin01-virtual-machine:~/Desktop$ reboot

8、测试root直接登录

 

root@liujiaxin01-virtual-machine:~/Desktop# whoami   ##直接登录成功
root

来源：https://blog.csdn.net/ht1032279753/article/details/107672004