Introduction CW Image Optimizer Plugin reduces image file size and improve performance using Linux image optimization programs. This will automatically and without any loss optimize the images as we upload them to your blog. It can also optimize the images that have already uploaded in the past. Because CW Image Optimizer uses lossless optimization techniques, your image quality will be exactly the same before and after the optimization. The only thing that will change is your file size.
TUN/TAP is a virtual network device that sends and receives packets to and from userspace rather than a physical interface. OpenVZ supports VPN inside a container via kernel TUN/TAP module and device.
Email authentication plays a critical role in improving email deliverability and protecting domains from spoofing. DomainKeys Identified Mail (DKIM) adds a digital signature to outgoing emails, allowing receiving servers to verify that messages are legitimate and unaltered. This guide explains how to install and configure OpenDKIM with Postfix to enable DKIM signing on a Linux server. What is OpenDKIM? OpenDKIM is an open-source implementation of the DKIM standard. It integrates with mail transfer agents like Postfix to automatically sign outgoing emails using cryptographic keys. Benefits include: Step 1: Install Required Packages Install the RPMForge repository and required packages. Step 2: Disable Sendmail Stop Sendmail and remove it from startup services. Step 3: Enable Services at Boot Enable Postfix and OpenDKIM …
ls command will surely be one of the most used command while working with Linux command line. Think of a situation when your ls binary get corrupted. Is there any alternative of “ls” command. The Answer is “YES” echo does ls
Email communication remains a critical component of modern infrastructure, and organizations often require reliable and secure mail transfer systems. Qmail is an SMTP-based Message Transfer Agent (MTA) designed for Unix environments. Known for its stability, security model, and ease of configuration, Qmail is often preferred over traditional solutions like Sendmail. This guide walks through the complete process of installing and configuring a Qmail mail server along with supporting utilities such as ucspi-tcp and daemontools, followed by enabling SMTP and POP3 services. Why Choose Qmail? Qmail provides several advantages: Prerequisites Before starting, ensure: Required Packages Download the following source packages: These components together provide mail transfer, networking utilities, and service supervision. Step 1: Preparing the Installation Environment Begin by creating the …
A sudden increase in server load can be alarming, especially on production systems. One common and often misunderstood cause is an active RAID resync or rebuild process. When a RAID array is rebuilding, the system performs intensive disk I/O operations, which can significantly impact overall server performance. Understanding how to identify and safely manage RAID rebuild load is essential for Linux administrators. Identifying RAID Rebuild Activity The first step when investigating unexplained load spikes on a Linux server is to check the RAID status using the following command: cat /proc/mdstat This file provides real-time information about all active software RAID arrays. If a rebuild or resync is in progress, you may see output similar to: md0 : active raid1 sda4[0] …
ProFTPD is a highly configurable FTP server that offers advanced control over user authentication and access management. However, standard FTP has a major security drawback—passwords are transmitted in plain text, making them vulnerable to network sniffing. To improve security, you can configure virtual FTP users using ProFTPD’s AuthUserFiles feature. This ensures that credentials are stored securely and not tied directly to system users. Why Use Virtual FTP Users? Using virtual users in ProFTPD helps you: Step 1: Install ProFTPD First, enable the RPMForge repository (if not already configured) and install ProFTPD: Step 2: Configure ProFTPD Edit the main configuration file: Disable default authentication methods Comment out the following line: Enable Virtual User Authentication Add the following configuration: Step 3: Create …
Setting the correct time zone on a Linux server is important for logs, cron jobs, monitoring tools, and applications. A wrong time zone can create confusion while debugging or tracking events. This guide explains both the modern and legacy ways to change the time zone in Linux. Step 1: Check the Current Time Zone Login to the server as root or a user with sudo access and run: date Example output: Wed Sep 12 15:13:14 IST 2012 Here, IST is the current time zone. Recommended Method (Modern Linux Systems) This method works on RHEL 7+, CentOS 7+, Rocky Linux, AlmaLinux, Ubuntu 16.04+, Debian, and most systemd-based systems. Step 2: List Available Time Zones timedatectl list-timezones You can scroll and …
Tmux is a software application that can be used to multiplex several virtual consoles, allowing a user to access multiple separate terminal sessions inside a single terminal window or remote terminal session. It is similar to screen as it lets you run numerous TTYs in the same terminal window. Tmux is a software application that can be used to multiplex several virtual consoles, allowing a user to access multiple separate terminal sessions inside a single terminal window or remote terminal session. It is similar to screen as it lets you run numerous TTYs in the same terminal window. To install Tmux, the following libraries should be installed on the server. libevent , libevent-devel How to install Tmux ? Download tmux …
an secure Mysql service using the following methods. 1. Restrict anonymous remote access :- Which meansnever provide grant access from all hosts. It must limit to specific users from specific hosts only. Do not grant the SUPER privilege and FILE privilege to non-administrative users. Any user who has this privilege can write a file anywhere in the file system with the privileges of the mysqld daemon. 2. Improve local security :- To improve local security use different socket file for both client and server connections. For that edit and add following line in the [client] section of /etc/my.cnf: [client] socket = /tmp/mysql.sock Also the following parameter should be added in the [mysqld] section in /etc/my.cnf: set-variable=local-infile=0 3. Change admin password …