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Articles by Satish Kumar
Page 28 of 94
How to Enable or Disable SELinux Boolean Values?
SELinux (Security-Enhanced Linux) is a security module that provides mandatory access control (MAC) to Linux-based systems. The SELinux module works by ensuring that each process and user on the system only has access to the resources they need. It does this by defining security contexts for processes, files, and other system resources. One of the key features of SELinux is its use of boolean values. These are binary options that can be set to either "on" or "off" to control specific policy behaviors without modifying the entire security policy. What are SELinux Boolean Values SELinux boolean values ...
Read MoreRepeat a Linux Command at a Given Interval
Linux is a powerful operating system that offers a wide range of command-line tools for executing various tasks. One task that often needs to be performed is repeating a command at a given interval. This feature can be useful for several reasons, such as monitoring system performance, running scheduled tasks, and performing automated backups. In this article, we will explore how to repeat a Linux command at a given interval. We will discuss various methods to achieve this, including using the cron utility, watch command, sleep command, and other scheduling tools. Using Cron to Repeat a Command ...
Read MoreHow to Enable PM2 to Auto Start Node.js App at System Boot?
PM2 is a process manager for Node.js applications that provides automatic restart on crashes, multi-application management, and detailed logging. It simplifies Node.js application management by automating common tasks like starting, stopping, and restarting processes while offering real-time performance monitoring capabilities. Enabling auto-start at system boot is critical for production Node.js applications. When servers restart for maintenance or updates, applications must automatically resume without manual intervention to ensure continuous service availability. Installing PM2 Before installing PM2, ensure Node.js is installed by running node -v in your terminal. If not installed, download it from the official Node.js website. ...
Read MoreHow to Add Hosts in OpenNMS Monitoring Server
OpenNMS is an open-source network monitoring and management platform that helps system administrators monitor their networks, servers, and applications. It provides comprehensive monitoring capabilities that allow administrators to detect and resolve issues before they become critical. In this article, we'll discuss how to add hosts in OpenNMS monitoring server. What are Hosts? Hosts are the devices or servers that you want to monitor. It could be a physical device or a virtual machine. In OpenNMS, hosts are represented as nodes in the system so that the monitoring system can track them for any issues that may arise. Adding ...
Read MoreHow to Enable RHEL Subscription in RHEL 8?
Red Hat Enterprise Linux (RHEL) 8 is a popular enterprise operating system known for its stability, security, and performance. Released in May 2019, RHEL 8 features a modular architecture allowing users to select specific components based on their needs. A crucial aspect of RHEL 8 is its subscription model, which provides access to software updates, security patches, and technical support. To fully utilize RHEL 8, users must have a valid subscription. Without it, you cannot access critical updates, security patches, or Red Hat's technical support, potentially exposing your system to security vulnerabilities and operational risks. Understanding RHEL Subscription ...
Read MoreRecursively List All Files in a Directory Including Symlinks
When managing files and directories in any operating system, being able to list all files in a directory is an essential task. However, it becomes more complex when you need to recursively traverse subdirectories and include symbolic links (symlinks). This is particularly important for system administrators and developers working with large, complex file systems where understanding the complete directory structure, including linked files, is crucial. What is a Symlink? A symlink (symbolic link or soft link) is a special type of file that acts as a pointer to another file or directory. It provides a way to create ...
Read MoreHow to Enable RPMForge Repository in RHEL/CentOS 8?
The RPMForge repository is a third-party package repository that contains various software packages not available in the default repositories of RHEL/CentOS 8. This repository provides additional software packages, updates, and patches that can be installed to enhance system functionality and performance. By enabling RPMForge, you gain access to a vast range of software packages for RHEL/CentOS 8 that are otherwise unavailable. System administrators and developers particularly benefit from this repository as it provides essential packages for development and system management tasks. Checking for Existing Repositories Before enabling RPMForge repository, check whether there are any existing repositories already ...
Read MoreAppend Lines to a File in Linux
Appending lines to a file is a fundamental Linux operation that allows you to add new content to existing files without overwriting their original contents. This is particularly useful for log files, configuration updates, and data collection tasks where preserving existing information is crucial. Using echo Command The echo command is the simplest method to append text to a file. It displays text and can redirect output using the append redirection operator >>. echo "New line of data" >> filename.txt The >> operator appends the text to the end of the file. If the ...
Read MoreHow To Enable SELinux In CentOS/RHEL 7?
SELinux (Security-Enhanced Linux) is a mandatory access control (MAC) security mechanism that provides an additional layer of security to the Linux kernel. By default, SELinux is enabled in CentOS/RHEL 7, but it runs in permissive mode, which means it logs security violations without blocking them. What is SELinux? SELinux is a security module developed by the NSA in partnership with Red Hat that enforces policies governing what actions processes and users can perform on the system. It uses predefined labels assigned to resources such as files, directories, sockets, and devices to define security contexts and control access. ...
Read MoreHow to Enable SSH on Debian 9 or 10?
SSH (Secure Shell) is a network protocol that enables secure communication between two systems. It establishes an encrypted connection to a remote server over unsecured networks like the internet, making it ideal for remote administration and file transfers. Unlike protocols such as Telnet or FTP, SSH encrypts all data transmission, preventing third-party interception. Importance of Enabling SSH on Debian 9 or 10 Enabling SSH on your Debian system provides crucial remote administration capabilities. System administrators can manage multiple servers from different locations without physical presence at each machine. This remote access minimizes infrastructure-related downtime by allowing quick issue ...
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