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Linux Articles
Page 98 of 134
How to Delete Iptables Rule?
Iptables is a powerful firewall tool built into Linux kernel-based operating systems that acts as a packet filter, monitoring and controlling network traffic based on predefined rules. As a system administrator, understanding how to delete iptables rules is crucial for maintaining and modifying firewall configurations when network requirements change. Understanding Iptables Rules Iptables works by analyzing incoming and outgoing data packets against a set of rules that determine whether traffic should be allowed, blocked, or forwarded. Each rule contains criteria such as source/destination IP addresses, ports, protocols, and actions to take when packets match those criteria. When ...
Read MoreHow to Delete Line in Vim on Linux?
Vim (Vi IMproved) is one of the most popular text editors used in the Linux environment. It is a command-line based editor that was initially developed as a free and open-source alternative to the widely-used Vi editor. However, Vim has evolved to be much more than just an alternative. It has become an indispensable tool for programmers, system administrators, and power users who work with text files regularly. One of the primary reasons why Vim is so important for Linux users is its efficiency and flexibility. Unlike traditional graphical user interface (GUI) editors, Vim focuses on quick navigation and ...
Read MoreHow to Delete Old Unused Kernels in CentOS, RHEL and Fedora?
Kernel management is a crucial system administration task in CentOS, RHEL, and Fedora. When you install kernel updates, the old versions are kept as a safety measure, but over time these can accumulate and consume valuable disk space, potentially causing boot issues or system slowdowns. Removing old unused kernels frees up disk space, reduces boot menu clutter, and eliminates potential security vulnerabilities in outdated kernel versions. However, it's important to always keep at least one or two recent kernels as backup in case the current kernel encounters issues. Checking the Current Kernel Version Before removing any kernels, ...
Read MoreHow to Enable NGINX Status Page?
NGINX is a high-performance web server that requires monitoring for optimal performance. The NGINX Status Page is a built-in module that provides real-time metrics about server activity, including active connections, request counts, and server uptime. This feature helps system administrators monitor performance, identify bottlenecks, and troubleshoot issues efficiently. Understanding NGINX Status Page The NGINX status page displays real-time performance data through the stub_status module. This lightweight monitoring tool provides essential metrics without significantly impacting server performance. Key Metrics Displayed The status page shows several important metrics − Active Connections − Current number of client ...
Read MoreHow to Enable NUX Dextop Repository on RHEL/CentOS 8
The NUX Dextop repository is a third-party package repository that provides multimedia and desktop packages for Red Hat Enterprise Linux (RHEL) and CentOS systems. Since RHEL/CentOS does not include multimedia software by default due to licensing restrictions, NUX Dextop serves as an essential source for media players, codecs, video editors, and desktop environment packages. This repository requires the EPEL (Extra Packages for Enterprise Linux) repository as a dependency, as it provides additional packages not available in standard RHEL/CentOS repositories. Prerequisites RHEL/CentOS 8 system with latest updates Root access or sudo privileges to execute commands Internet connection ...
Read MoreHow 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 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 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 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 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. ...
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