There are three main ways to become a root user in Linux: 1. Use the su command to switch, enter su - and provide the root password; 2. Execute a single command through sudo or use sudo -i to enter the root shell; 3. Log in directly as root (not recommended), you need to set the password and modify the SSH configuration. It is recommended to give priority to the use of sudo to ensure safety.

Becoming a root user in Linux is actually to obtain the highest permissions of the system, which is convenient for performing some operations that require administrator permissions, such as installing software, modifying system configurations, etc. There are several implementation methods, and each applicable scenario is slightly different.

Use the su command to switch to root

This is one of the most traditional ways to work with most Linux distributions. You just need to enter:

 su -

Then enter the root user's password. If the root password has not been set, it may be locked by default (especially for systems like Ubuntu).

What should be noted is:

• Some systems do not set passwords for root by default, you need to use sudo passwd root to set them first.
• Use the - parameter to load the root environment variables, and it is also recommended to use the full command su - .

Use sudo to execute a single command or switch users

If you just want to run a command that requires permissions and don't need to switch to root completely, you can use sudo :

 sudo command

For example:

 sudo apt update

If you want to go directly to the root shell, you can do this:

 sudo -i

or:

 sudo su -

But note: sudo su - actually execute su - as an ordinary user first, which is not necessarily the best practice. It is recommended to use sudo -i first.

To use sudo , your user must be authorized in the sudoers file. The main user is usually automatically added to the sudo group when the system is installed.

Log in directly as root (not recommended)

On some servers or custom systems, you can log in as a root user directly, but this poses a security risk, especially on machines exposed on public networks. Most modern distributions disable root login by default to avoid misoperation and improve security.

If you really need to enable root login (for example, for SSH), you can do this:

• Set root password
• Modify the PermitRootLogin option in the /etc/ssh/sshd_config file to yes
• Restart the sshd service

However, this is not recommended unless particularly necessary.

Basically these are the methods. It is recommended to use sudo to temporarily increase power, which is both safe and convenient. If you really want to operate the root environment for a long time, use sudo -i or su - to cut in, remember to exit in time after the operation.

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