Linux login as root

How Can I Log In As root User?

It is not good a 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.

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.

su command syntax

If invoked without a user-name, su defaults to becoming the super user. The user will be prompted for a password, if appropriate.

To log in as root user type the following command (you need to supply root user account password when prompted):
$ su —
Sample outputs:

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

Remote root login over the ssh session

You can use the ssh client as follows:
$ ssh root@server.ip-address-here
$ ssh root@server1.cyberciti.biz
$ ssh root@1.2.3.4
However, remote root login over ssh session is disabled in most cases for security reasons. First, login as a normal user and then switch to root account using the su command:

## login as a normal user ## ssh user1@server1.cyberciti.biz ## now switch to root account ## su —

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:
# tail -f /var/log/secure
Debian / Ubuntu Linux user try:
# tail -f /var/log/auth.log
Sample outputs:

Say hello to sudo command

The sudo is a program for Linux / Apple OS X / *BSD / Unix-like computer 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. Apple Mac OS X and Ubuntu Linux and many other oses 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 example, to login as root under Linux or Unix like operating system, type:
$ sudo -s

Sample sudo command session

Fig.01: Switching to root account using sudo command

Sudo and log file

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

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Remote login as root in ubuntu

In my project, I have to install some package remotely. If I have to login in debian, I say:

it logs in successfully.

I have login in ubuntu in directly using

it is throw error message in

How to solve this problem?

10 Answers 10

By default, the Root account password is locked in Ubuntu.

Please keep in mind, a substantial number of Ubuntu users are new to Linux. There is a learning curve associated with any OS and many new users try to take shortcuts by enabling the root account, logging in as root, and changing ownership of system files.

It talks at length about why it’s been done this way.

Enabling the root account:

To enable the Root account (i.e. set a password) use:

Use at your own risk!

Logging in to X as root may cause very serious trouble. If you believe you need a root account to perform a certain action, please consult the official support channels first, to make sure there is not a better alternative.

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How do I login as root?

I want to login as root, but when I enter

and enter password, this message is shown: «you are not in sudoers file», and when I enter

and enter password, this is shown: «authentication failure».

My os has one account only. about past1 hours ago I log on as root and do some commands , when I logout , I can’t login another time!

4 Answers 4

The su command requires you to put in root password. Root user on Ubuntu in general is locked so no user can login as root thus su is not likely to work.

For sudo -s to work you will have to be part of the admin group on an Ubuntu machine, which apparently you are not.

If you are the only user on the system that is concerning and may be quite involved to fix. If not I would suggest you talk to the System Administrator or owner of the system to see if you even can get root privileges.

Be aware that the root account is not active by default.

You will need to do:

Then go ahead to set password. Use the root user using

If you really need a persistent Root login, the best alternative is to simulate a Root login shell using the following command.

First of all you need to have admin privileges. If you don’t have admin privileges then while booting press and hold the shift key. You will enter the GRUB menu. Here select recovery mode. When you see the list of options like dpkg etc, choose to start a root shell and type:

(where username is your username 🙂 )

this will add you to the sudoers group! Then type exit and boot normally. when you enter your account, type:

Then enter your password and type the new root password

After that you can type su and enter the ‘root’ password.

If you don’t want to change the root password then you can use:

to start a root shell, using your own password.

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Linux Login as Superuser ( root user )

Linux superuser

In Linux and Unix like computer operating systems, root is the conventional name of the user who has all rights or permissions (to all files and programs) in all modes (single- or multi-user). The root user can do many things an ordinary user cannot, such as changing the ownership of files and binding to ports numbered below 1024. The etymology of the term may be that root is the only user account with permission to modify the root directory of a Unix system.

Linux Login as Superuser

You need to use any one of the following command to log in as superuser / root user on Linux:

1. su command – Run a command with substitute user and group ID in Linux
2. sudo command – Execute a command as another user on Linux

How to become superuser in Linux

Let us see some examples of the su and sudo command to become superuser in Linux.

Become a superuser in Linux using sudo command

You must be part of special secondary group on Linux:

• sudo group on a Debian or Ubuntu Linux
• wheel group on a CentOS/RHEL/Fedora/Oracle Linux

You can see your secondary group membership by running either groups command or id command $ groups
$ id
Next run the following command to become a root/super user:
$ sudo -i
When promoted type your password to gain root shell.

Log in as a superuser/root user using the sudo command on Linux

Superuser login � How to become Superuser in Linux using su

Under Linux (and other Unixish operating systems) you use command called su. It is used is used to become another user during a login session or to login as super user. If invoked without a username, su defaults to becoming the super user. It is highly recommend that you use argument — to su command. It is used to provide an environment similar to what the user root would expect had the user logged in directly. Type su command as follows:
$ su —
Sample outputs:

Once you typed the root user password, you become super or root user.

Exiting from su or sudo session

You simply need to type the following exit command or logout command:
exit
OR
logout
Another option is to press the CTRL and d keys simultaneously to exit from su or sudo session:

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Information Security Squad

stay tune stay secure

🐧 Как стать пользователем root на Linux

Пользователь root — это суперпользователь Linux, который похож на администратора на Windows.

Он может выполнить все виды административных операций, поэтому никому не предоставляйте root-права, поскольку они могут повредить вашу систему, если они не знакомы с Linux.

Отключение root является безопасным подходом, в UBUNTU как правило это реализовано и предоставляется пользователь sudo вместо root-доступа.

Чтобы справиться с этой ситуацией, вы можете позволить обычному пользователю выполнять административные задачи с помощью команды sudo.

Если вы не знаете, как настроить доступ sudo в Linux, обратитесь к следующей статье.

Вы можете точно отслеживать активность пользователя, когда включаете ему доступ sudo.

Система записывает все в журнал сообщений (/var/log/message).

1) Как стать пользователем root на Linux с помощью команды su

Команда su (сокращение от «substitute» или « switch user» или «super user») позволяет вам запускать команды с привилегиями другого пользователя, по умолчанию пользователь root.

su — самый простой способ переключиться на учетную запись root в Linux, но для использования команды su в Linux вы должны знать пароль root.

Это позволит вам получить домашний каталог пользователя root и его оболочку.

Когда вы вошли в систему от пользователя root, командная строка заканчивается # вместо $.

Вы можете задаться вопросом, почему я должен использовать «-» при использовании команды su, и в чем разница.

• su -: когда вы используете «su -», система устанавливает целевую пользовательскую среду, включая HOME, SHELL, USER, LOGNAME и PATH.
• su: Сохраняет текущую пользовательскую среду.

2) Как стать пользователем root на Linux с помощью команды «sudo -i»

Команда sudo (сокращение от super user do) позволяет временно запускать другие команды от имени пользователя root.

Это лучший способ выполнять команды от пользователя root, потому что система записывает все, что вы делаете с помощью команды sudo.

Пользователю не нужно знать пароль пользователя root, чтобы стать пользователем root.

Вместо этого пользователи будут вводить свой собственный пароль, чтобы получить временный root-доступ.

Система предоставит вам интерактивную рут оболочку, и вы попадете в домашний каталог рута (/root).

Кроме того, вы можете запустить команду прямо из сеанса, добавив sudo перед каждой выполняемой командой.

3) Как стать пользователем root на Linux с помощью команды «sudo -s»

Система даст вам root-доступ, но защищает вашу текущую среду, включая специфические для оболочки настройки и домашний каталог.

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