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In Linux or Unix-based operating system, there are two types of users: a superuser (root) and a normal or regular user. The root user has full control of the operating system and it has privileges to run administrative commands like installing, removing, and updating software packages, changing permissions, and configuring different services. The non-root users have limited interactions with an operating system environment and they can perform only user-specific tasks.

The sudo command, short for “super-user do,” is a Linux utility that allows a normal user to run any commands with unlimited privileges. In this case, you will need to add a normal user to the sudo group in order to execute administrative commands.

In this post, we will show you how to create a sudo user in Rocky Linux 8.

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SSH, also known as a “Secure Shell Protocol,” is a protocol used to access a remote Linux system securely over an unsecured network via the command-line interface. SSH allows users to run commands on remote Linux servers, install and remove software packages, and manage everything via command line from a single place.

If you are a Linux system administrator and managing multiple servers via SSH, then you may need to provide a root password each time when you connect to the remote server. Remembering passwords for thousands of servers is very difficult for an administrator. In this case, you can use an SSH public and private key pair to connect remote servers without entering a password.

In this post, we will show you how to create a public and private key and set up a Linux server for passwordless login.

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In Linux, an instance of a running service, application, or script is called a process. When you run any command, program, or application, a process is created for it. Each process has its own process id that is associated with a specific user and group. If any processes consume too many resources or become unresponsive, then you may need to kill them. In this case, you can use the kill command to stop the process without restarting your server.

In this post, we will show you how to kill running processes in Linux.

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If you are a Linux user and work with many files at a time, then you may often face the error “Too many open files” on Linux. This is because you have reached the maximum open file limit set by Linux operating system. In this case, you can use the ulimit command to change the default limit set by the operating system.

The max open file limit is very useful to prevent your system from sudden crashes. There are two types of open file limits in Linux.

• Hard Limit: This limit can only be modified by the root user.
• Soft Limit: This limit can be modified by any normal user. It indicates the current value of the session or user.

In this post, we will show you how to change the open file limit on Linux.

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A Port is a logical number assigned to a process running on Linux. Port can be defined as an integer number between 0 to 65535. Ports with numbers 0–1023 are called system or well-known ports, while ports with numbers 49152-65535 are called dynamic, private, or ephemeral ports. If you are a Linux system administrator then you should have the knowledge to find out which ports are open and running on a remote system. There are several ways to find an open port on Linux.

In this post, we will show the most reliable ways to find an open port on a remote Linux system.

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