Logging as root in linux

How to log in as root in linux shell?

This works on systems where sudo is inavailable or not configured.

Some distributions disallow logging in as root and then one should run his commands like this:

If you need to run a lot of commands as root but are forced to use sudo, sudo -s will get you a root shell too.

I’d comment on sagar’s answer if I could, as I wish to add that while

will log you in as root in the shell, it will move you to its home directory (/root) as well.

Edit: As said by Andreas,

would instead allow you to remain in your current directory, which may be useful.

How to use this together with the -S flag in this fashion: echo «mypassword» | sudo -Si ? Its not working and telling me -bash: line 1: mypassword: command not found .

use sudo -i command and put your current user password

Reboot the computer. In the LILO boot loader, we should press Ctrl + X and type “linux single”. The sh-3.00# prompt should be displayed when Linux starts.

Type “passwd” and type the new password we want to use. Linux will ask us again to type the same password as confirmation.

Reboot the computer and start Linux normally. We should be able to login as root at the login screen. See How to Log In and Work as Root in Linux

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How to become root in Linux

On every Linux system, the root account is a special user with administrative rights. Logging in as root (or executing commands with root privileges) is necessary for many tasks. If you need to perform tasks as the root user, make sure you fully understand the commands you are running, and what consequences they have. A single careless or malformed command, run as root, can make the entire operating system unusable. Do your research, and always double-check every command before pressing Enter .

Logging in as root

The root account is similar to any other account in that it has a username («root») and a password. If you know root’s password, you can use it to log into the root account from the command line.

There is a special command named su (for «super user,» or «switch user») that lets you run commands as the root account temporarily. From the command line, type:

Enter the password once prompted for the password. If successful, you are switched to the root user and can run commands with full system privileges.

Be careful while logged in as root. It is easy to forget you’re currently the root user, and you might inadvertently run a command thinking you are only a mere mortal. One way to remind yourself if you are root or not is to check your command prompt. Many systems end their command prompt with a dollar sign («$«) if you’re logged in as a normal user and a pound sign («#«) if you’re root.

Or, you can use the whoami command to determine the account you are using.

When finished with your administrative tasks, you can run the exit or logout command to return to your standard user account.

When logging in as root, it is often useful to use a single dash after the su command, like this:

This command simulates a complete root login. It executes all of the root user’s shell initialization scripts and sets all environment variables as if the root logged in to a fresh shell session. Depending on what task you need to perform, and how root is configured, this form of the su command might be optimal for you.

Running commands as root without the root password

It is possible, and often preferable, to run commands as root without logging into the root account using the sudo command, which stands for «superuser do.» If you prefix a command with sudo, you are prompted for your password (not the root password), and your name is checked against a special file called sudoers. If your account is listed there, your command runs with root privileges.

Using sudo makes it difficult to forget you’re root since you’re not logged in to the root account, and are never going to forget to log out. Also, typing sudo every time you run a potentially destructive command reminds you to be extra careful and double check yourself.

If you need to add a user to the sudoers list, use the visudo command that requires root privileges to run, and lets you safely edit the sensitive sudoers file.

Related information

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Login as Root in Ubuntu GUI

If you really want it, you can log in as root into the Ubuntu desktop using GNOME. Here’s how to do that.

By default, Ubuntu disables the root account. You must use the sudo command for any tasks requiring root privileges. This is for your own security, of course. Using the system as root all the time is like running around with a sword in your hand. It increases the chances of messing up things. Logging in as root is still common in the servers. On the desktop side, it’s quite rare to log in as root. Even Kali Linux has changed it. And yet, a few desktop users want to log in as root. This is not something advisable but surely doable. in this guide, I will show you how to log in as a root in your GNOME desktop using Ubuntu.

How to login as a root in the GNOME desktop

I won’t advise login as root on the desktop. You have sudo mechanism for all your root needs. Do it only if you have a good enough reason. This tutorial is for demo purposes only. You have been cautioned.

Step 1: Enable root account

You want to log in as root. But the root account is disabled by default. The first step is to enable it. Change the root account password that will eventually enable the root account for you:

It goes without saying that you should not forget the root password.

Step 2: Change GDM configuration

This part of the tutorial is only valid for GNOME. Please check your desktop environment and ensure that it is GNOME.

Ubuntu uses GNOME by default and GNOME uses the GDM display manager. To allow log in as root into GNOME, you need to make some changes in the GDM configuration file located at /etc/gdm3/custom.conf . Make a backup of the config file:

cp /etc/gdm3/custom.conf /etc/gdm3/custom.conf~ 

In the worst case, if you somehow mess things up, the back up file can be used to replace the existing one from the TTY. Now, open the GDM file with the following command:

sudo nano /etc/gdm3/custom.conf 

Press Ctrl+X to exit Nano while saving it.

Step 3: Configure PAM authentication

Now, you will have to configure the PAM authentication daemon file, which can be opened by the following command:

sudo nano /etc/pam.d/gdm-password

In this file, you will have to comment out the following line with the # symbol that denies the root access in GUI:

auth required pam_succeed_if.so user != root quiet_success

Save changes and exit from the nano text editor.

Step 4: Log in as root

At the login screen, select the Not listed option, enter root in username and enter the password that you configured at the beginning of this guide: Once you log in, it will notify you by saying, «logged in as a privileged user»: That’s it! Now, you are running your Ubuntu system as a root.

Things you should know when running the system as a root user

There is a reason why Ubuntu disables a root account by default. Want to know why? Here you have it: And again, it is not advisable to log in a s root in your desktop Linux system. Please follow the norms and stay away from such (mis) adventures.

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How to log into your Linux Server as a root user?

On Linux operating systems, the root user act as a superuser. The root account has root privileges. What this means is that it can read and write any files on the system, perform operations as any user, change system configuration, install and remove software, and upgrade the operating system and/or firmware. In essence, it can do pretty much anything on the system.
Here at LinuxAPT, as part of our Server Management Services , we regularly help our Customers to perform Software Installation tasks on their server.
In this context, we shall look into how to run commands as root user using nonuser, su, and sudo utilities.

More about Root user on Linux?

Root user is the conventional name of the user who has all rights or permissions on the system. The root user can do many things an ordinary user cannot, such as changing the ownership of files, mounting disk, formatting & restating new file system, starting/stopping services, and binding to ports numbered below 1024 and any other tasks.
Basically, it is not a good practice for anyone to use root as their normal user account, because of security risks. Therefore, you use a normal user account instead. You need to use the su or sudo command to switch to root user account.

Here we will look into some commands which root user enjoys.

1. su command.

The su command is use to change user ID or become super-user during a login session i.e. it allows you to become a super user or substitute user, spoof user, set user or switch user.

Note: su only works if you know the target or root user’s password.

What is the su command syntax?

If used without a user-name, su defaults to becoming the super user. The user will be prompted for a password accordingly.
To log in as root user type the following command (you need to supply root user account password when prompted):

You will get an output such as;

Once logged in, your prompt should change from $ to # . To log in as another user say linuxapt, run the following command (you need to supply linuxapt user account password when prompted):

You will get an output such as this;

2. How to establish Remote root login over the ssh session?

Now with an ssh client tool such as putty, you can run the following command;

$ ssh root@server.ip-address-here

$ ssh root@server1.linuxapt.com

In some cases, the remote root login over ssh session is disabled in most cases for security reasons.
Start by logging in as a normal user and then switch to root account using the su command as shown below;
## login as a normal user ##

ssh user1@server1.linuxapt.com

## now switch to root account ##

3. More about su command and log files?

The su command logs its usage in a system log file. This is useful to find out su login information.
If you are RHEL / CentOS / Fedora Linux user type the following as root to see the contents of » /var/log/secure «, execute the command:

For Debian / Ubuntu Linux user, execute:

4. More about sudo command?

The sudo is a program for Linux operating systems that allows users to run programs with the security privileges of another user, normally the superuser (root). By default, sudo will prompt for a user password but it may be configured to require the root password or no password at all. Ubuntu Linux and many other Operating system uses sudo command for many administrative tasks.
sudo executes a command as another user but follows a set of rules about which users can execute which commands as which other users. This is configured in a filed named /etc/sudoers . Unlike su, sudo authenticates users against their own password rather than that of the target user. See how to configure and use sudo tool under Linux operating system.

For instance, to login as root under Linux, execute the command:

Then your will be prompted to enter a password. Once you enter the password, you will be logged in as the root and you will be able to enjoy sudo privileges.

5. How to work with Sudo and log file?

The sudo log can be viewed by issuing the following command as root user:

## Generic file for Unix/Linux ##

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Conclusion

This article will guide you on how to run commands as root user using nonuser, su, and sudo utilities.

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