How to Configure an Additional IP as an Alias in Ubuntu

Managing resources efficiently is vital for maintaining the performance and stability of the OS. In this article, the methods of adding swap space to Ubuntu 22.04 is outlined to help users boost their platform's capacity to carry on memory-intensive activities. Swap space acts as a virtual extension of physical memory (RAM), allowing the system to offload inactive processes when it is fully utilised. While Ubuntu 22.04 is highly efficient in memory management, adding or increasing paging area can be a practical solution for environments with small data storage unit or when running resource-heavy applications. This article provides a step-by step approach in creation, configuration, and optimisation of swap space, ensuring a smooth and efficient setup tailored to everyone's needs. Prerequisites Before adding swap space on Ubuntu 22.04, make sure the following prerequisites are satisfied to avoid potential issues: Administrative Privileges: User must have root or sudo access to the platform to execute commands for creating and configuring swap space. Existing Disk Volume: Confirm that the instance has sufficient free disk storage to allocate for the desired swap size. Deploy the following instruction to check disk space: df -h Current Status: Determine whether a swap space already exists and come up with the decision to expand it. Utilise the instruction below to verify: sudo swapon --show Suitable Performance Needs Assessment: Determine the required capacity of the swap space according to the current storage resource and workload. A common rule is to have at least same amount as the RAM size, but this may vary depending on your use case. What is Swap A crucial part of Linux memory management, swap space is intended to improve system performance and stability by increasing the system's accessible capacity beyond the physical random-access memory (RAM). The OS frees up memory for running processes by offloading idle or seldom used data to the paging space area when the RAM is completely utilised. This procedure enables the system to manage resource-intensive tasks more effectively and keeps apps from crashing because of memory shortages. Depending on the demands of the user, swap can be implemented in Ubuntu as a file or as a separate disc. This can be useful, but it cannot take the place of enough RAM. Because disc storage has slower read and write rates than physical memory, an over-reliance on this might result in performance loss. Optimising system performance requires an understanding of swap's operation and proper configuration, especially for tasks like managing apps on platforms with limited RAM, operating virtual machines, or compiling huge codebases. Swap Advantages Swap space is an important part of Linux environment memory management because it provides a number of benefits. The following advantages are offered by swap: Prevents System Crashes Supports Memory-Intensive Applications Enhances Multitasking Smoother multitasking without sacrificing speed for platforms managing numerous processes at once by balancing memory use by offloading less important operations. Provides Flexibility Swap space allows for the dynamic addition or resizing of paging space, which facilitates system requirements adaptation without requiring disc repartitioning. Extends Uptime Period It is a short-term fix to increase stability and prolong its uptime under high loads in situations where replacing physical memory is not immediately practical. Facilitates Hibernation Swap is crucial for systems set up to utilise the hibernate feature since it keeps the contents of the RAM in place when the system is turned off, enabling a smooth restart. Supports Low-Memory Systems For lightweight systems, this is beneficial because it guarantees that critical operations continue to run even when memory is limited on devices with little physical memory. Swap is essential for increasing overall system resilience and flexibility, especially in resource-constrained contexts, even while it cannot replace physical RAM and shouldn't be over-relied upon. Swap Disadvantages Although swap space has several benefits for memory management, there are a few significant drawbacks that should be taken into account when setting it up. Slower Performance Compared to RAM Increased Disk Wear Latency in Resource-Intensive Tasks When the system relies heavily on swap, tasks that require high memory bandwidth, such as video editing or large-scale data analysis, may experience significant delays due to slower data transfer rates. Limited Effectiveness in Low-RAM Scenarios While swap can extend memory, it is not a substitute for adequate RAM. On systems with extremely low physical memory, relying on swap may not be enough to handle modern applications efficiently. Hibernation Dependency If the swap space is insufficient, hibernation may fail as it requires swap to store the contents of the RAM. Misconfigured swap sizes can lead to system errors during hibernation attempts. Additional Storage Allocation Allocating swap space reduces the available storage for other purposes. For systems with limited disk capacity, dedicating a portion to swap may not be feasible. Complexity in Configuration Optimising swappiness and settings require careful planning and monitoring. Poor configuration may lead to either underutilisation or excessive reliance, both of which impact system performance. How to Add Swap Space by Creating a Swap File Making a swap file in Ubuntu 22.04 to increase swap space is a simple procedure that can assist boost system performance, particularly on systems with low RAM. Here is a thorough, step-by-step guide to assist you with the process: Make sure swap space is enabled before making a new file. Run the instruction below. sudo swapon --show Based on the RAM capacity and usage needs, choose the swap file's size. A typical rule of thumb is: For systems with less than 2 GB of RAM, swap size is equal to RAM size × 2. For systems with more than 2 GB of RAM, swap size equals RAM size. Choose the location of the file, which is often the root directory. Adjust to the user's preferred swap size. To do it, use the fallocate command. sudo fallocate -l 4G /swapfile If fallocate is unavailable or gives an error, employ the dd command. sudo dd if=/dev/zero of=/swapfile bs=1M count=4096 bs=1M: Sets the block size to 1 Megabyte. count=4096: Creates a 4GB file (4096 × 1MB). Verify that the permissions are configured appropriately to prevent unauthorised access. Execute the following command. sudo chmod 600 /swapfile It is necessary to format the file as swap space. After that, swap can be activated. Execute the command listed below.       sudo mkswap /swapfile sudo swapon /swapfile To verify if it has been added, use the instructions listed below, appropriately. sudo swapon --show free -h Add the swap file to the /etc/fstab file to guarantee it stays active following a reboot. Perform the following steps. Backup the fstab file before editing. sudo cp /etc/fstab /etc/fstab.bak Add the swap record in fstab. echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab Validate using command below. cat /etc/fstab Configuring Swappiness (Optional) Swappiness controls the kernel's use of swap space. 60 is the default value. Usage rises with higher values and falls with lower values. Verify current swappiness value by running command below. cat /proc/sys/vm/swappiness Use the sysctl utility to temporarily modify the swappiness. The value is lowered to 40 from 60 by the subsequent command. sudo sysctl vm.swappiness=40 To make the changes permanent, run these commands respectively. echo 'vm.swappiness=40' | sudo tee -a /etc/sysctl.conf sudo sysctl -p Modify Cache Pressure (Optional) Cache pressure regulates the kernel's propensity to recover caching memory, which can be lessened with lower values. If for example, a user wants to set VFS Cache Pressure to 40, this can be set using the commands below respectively. echo 'vm.vfs_cache_pressure=40' | sudo tee -a /etc/sysctl.conf sudo sysctl -p Verify that the swap file is operational and set up properly. Use the commands below to check it. sudo swapon --show free -h Increasing Swap Space with Swap File To resize the system's swap file, use the following actions. Temporarily disable the swap file. sudo swapoff /swapfile Change the size of the swap file to the preferred size. Replace 8G with your desired new size. Using the fallocate command sudo fallocate -l 8G /swapfile Using the dd command sudo dd if=/dev/zero of=/swapfile bs=1M count=8192 To adjust for the new size, reinitialise the swap file. sudo mkswap /swapfile Activate the swap file that has been resized. sudo swapon /swapfile Validate that the swap space has been updated from 4GB to 8GB. sudo swapon --show free -h Conclusion To sum up, creating a swap file in Ubuntu is a simple procedure that can greatly improve system speed, especially when working with memory-demanding apps or when physical RAM is at limited availability. Without the need for intricate partitioning, users can rapidly increase the virtual memory of their system by following the instructions to create, format, and activate a swap file. The swap space will also be active across reboots if the swap file is made permanent via the /etc/fstab file. The memory management can be further optimised by modifying variables like swappiness. All things considered, making a swap file is a practical and adaptable way to enhance Ubuntu system efficiency and stability. You can install Ubuntu on a VPS on Hostman.

In this guide, we will describe installing PHP and PHP-FPM on Ubuntu 24.04. PHP, which stands for Hypertext Preprocessor, is a language that is widely used and open-sourced, mainly for web development. PHP is the only PHP FastCGI implementation, that is extremely useful for high-traffic websites. At the end of this guide, you should be ready to go with PHP running on your server. Prerequisites Before we start, please confirm you have the following: Ubuntu 24.04 LTS installed on the server A user account with the sudo access An essential command-line operation understanding A reliable internet connection for downloading software packages To ensure that your system is up to date, run the following commands: sudo apt updatesudo apt upgrade Install Apache Launch the Apache web server using the following command: sudo apt install apache2 Install PHP Let's begin with installing the PHP package in Ubuntu 24.04 server. First, open a terminal on your Ubuntu system. PHP and common modules are included in the installation action: sudo apt install php That command installs the core PHP package, the command-line interface, and common libraries. Make sure the installation works: php -v Install PHP Extensions PHP extensions are the way to go to extending PHP installation with certain functions. Start by installing extensions: sudo apt install php-curl php-mbstring php-xml Short description: php-mysql: Allows MySQL database connection php-gd: Adds ability to manipulate images php-curl: Makes possible to communicate with servers php-mbstring: Provides multibyte string support php-xml: Enables XML support php-zip: Enables ZIP support Additional extensions can be installed as you see fit for your projects. You can search them using: apt-cache search php- Install and Configure PHP-FPM PHP-FPM is essential when dealing with high-traffic websites. To install and configure it: Install the package: sudo apt install php-fpm Launch PHP-FPM service. Depending on the installation, version number may differ. sudo systemctl start php8.3-fpm Tell PHP-FPM to go on boot: sudo systemctl enable php8.3-fpm Verfy PHP-FPM is working: systemctl status php8.3-fpm This will output a response that says "Active (Running)" if everything is working as expected. Test PHP and PHP-FPM To ensure that PHP and PHP-FPM are both running with no problems, create a test file then serve it via the website's server. Let's say it uses Apache in this example: Generate PHP Info File. To show PHP settings using the phpinfo() function, do the following: mkdir -p /var/www/htmlecho "<?php phpinfo(); ?>" | sudo tee /var/www/html/info.php Set Up Apache for PHP-FPM. Ensure Apache is made compatible for PHP-FPM, by first finding Apache configuration file (usually /etc/apache2/sites-available/000-default.conf) then inserting: <FilesMatch \.php$>   SetHandler "proxy:unix:/var/run/php/php8.3-fpm.sock|fcgi://localhost/"</FilesMatch> Remember we must alter specific PHP version and socket path to suit individual settings of the server. Activate PHP and PHP-FPM. Enable PHP and PHP-FPM following these instructions: sudo apt install libapache2-mod-phpsudo a2enmod proxy_fcgi setenvif Reboot Apache. Apply changes by restarting Apache server: sudo systemctl restart apache2 Access PHP Info Page. First open your web browser and go to: http://your_server_ip/info.php Replace [server_ip] with the server IP address or domain. You can see details of your PHP installation. Install Multiple PHP Versions For particular projects you might need to run different applications, each one may require different functionalities. This is the way to manage and manipulate multiple PHP versions on Ubuntu 24.04. First, add PHP repository: sudo apt install software-properties-commonsudo add-apt-repository ppa:ondrej/php && sudo apt update Install PHP versions you need: sudo apt install php8.1 php8.1-fpm Deselect one PHP version and elect the other: sudo update-alternatives --set php /usr/bin/php8.1 If you are using multiple PHP versions, ensure that your web server is pointing to the appropriate PHP-FPM socket. Securing PHP and PHP-FPM: Best Practices As a web developer, you know the importance of incorporating both PHP and PHP-FPM into web applications that are safe and robust. In this section, we will introduce a number of security steps that you should adapt using PHP and PHP-FPM. 1. Keep PHP and PHP-FPM Updated PHP and PHP-FPM should be up to date. Doing regular updates will eliminate known security breaches and provide overall security improvements. You need to check for updates as often as possible then update the system as soon as the updates are available. 2. Configure PHP Securely To configure PHP securely, start by disabling unnecessary and potentially dangerous functions, such as exec, shell_exec, and eval, in the PHP configuration file (php.ini). Use open_basedir directive to restrict PHP’s access to specific directories, preventing unauthorized access to sensitive files. Set display_errors to Off in production to avoid exposing error messages that could provide insights to attackers. Limit file upload sizes and execution times to reduce the risk of resource exhaustion attacks. Besides, ensure that PHP runs under a dedicated, restricted user account with minimal permissions to prevent privilege escalation. Regularly update PHP to the latest stable version to patch vulnerabilities and improve security. 3. Use Safe Error Reporting To ensure an error-free application, it is quite handy locating and correcting code bugs in a development environment. In production environment, you have the possibility to hide the PHP errors by setting the display_error directive to be off, and you should also set the log_errors directive to be On, thus this will help you prevent PHP from showing errors to the users whereas your server will log it in a safe location without problems to users. 4. Implement Input Validation Being aware of the input validations is quite crucial during the programming of your software. Make sure that all deficiencies are tested and only SQL statements containing their SQL equivalent that can produce outwardly neutral queries via prepared statements is considered safe. 5. Secure PHP-FPM Configuration PHP-FPM is required to run using a non-usual user account with minium rights. Furthermore, access to the PHP-FPM socket or port should be very limited to the web application. 6. Enable Open_basedir You need to bind open_basedir directive in order to restrict access files within the given directory. In this case, if you attempt to visit a forbidden directory and the request is accidentally transmitted to the server, PHP will prevent you from doing so. 7. Use HTTPS We need to secure web calls by making apps HTTPS-only, which is the only prominent way to block all the known hacking tricks. Conclusion With this guide, you've successfully set up PHP and PHP-FPM on Ubuntu 24.04. Your server is now configured for dynamic web applications. To maintain security and performance, remember to keep the system and packages regularly updated.

PHP is a scripting programming language commonly used for developing web applications. It allows developers to create dynamic websites that adapt their pages for specific users. These websites are not stored on the server in a ready-made form but are created on the server after a user request. This means that PHP is a server-side language, meaning scripts written in PHP run on the server, not the user's computer. There are many different versions of PHP. The language becomes more powerful and flexible with each new version, offering developers more opportunities to create modern web applications. However, not all websites upgrade or are ready to upgrade to the latest PHP version and remain on older versions. Therefore, switching between versions is an essential task for many web developers. Some developers want to take advantage of new features introduced in newer versions, while others need to fix bugs and improve the security of existing applications. In this article, we will go over how to install PHP on Ubuntu and how to manage different PHP versions. How to Install PHP on the Server To install PHP on Ubuntu Server, follow these steps: Connect to the server via SSH. Update the package list: sudo apt update Install the required dependencies: sudo apt install build-essential libssl-dev Download the installation script from the official website, replacing <version> with the desired version: curl -L -O https://www.php.net/distributions/php-<version>.tar.gz Extract the downloaded file, replacing <version> with the downloaded version: tar xzf php-<version>.tar.gz Navigate to the directory with the installed PHP: cd php-<version> Configure the installation script: ./configure Build PHP: make Install PHP: sudo make install After completing these steps, PHP will be installed on your server. The next step is to install a web server to work with PHP. The configuration may involve specifying the PHP module in the web server configuration file and setting up how .php files are handled. Finally, restart the web server. For example, to restart Apache, you can run the following command: sudo service apache2 restart How to Check PHP Version There are several ways to find out which version of PHP a website is running: Use the terminal. Create a script with phpinfo() in the website's root directory. Check PHP Version via Terminal Run the command in the terminal: php -v You will get output similar to: PHP 8.3.13 (cli) (built: Oct 30 2024 11:27:41) (NTS)Copyright (c) The PHP GroupZend Engine v4.3.13, Copyright (c) Zend Technologies    with Zend OPcache v8.3.13, Copyright (c), by Zend Technologies Check PHP Version with phpinfo() Create a file named phpinfo.php with the following content: <?phpphpinfo( );?> Save the file in the root directory of your website (where the index.html or index.php file is located). Open this file in your browser by using the following URL: http://your_website_address/phpinfo.php You will see a page with detailed information about the PHP configuration. After finding out the PHP version, be sure to delete the phpinfo.php file as it contains important server configuration information that attackers could exploit. How to Manage PHP Versions To switch between installed PHP versions on Ubuntu, follow these steps. Check if multiple PHP versions are installed. To see the list of installed PHP packages, run the command: dpkg --list | grep php Install the php-switch package, which allows change PHP versions easily: sudo apt-get install -y php-switch Switch to the desired PHP version using the php-switch command. For example, to switch to PHP 7.4, run: php-switch 8.2 Verify which PHP version is currently active by running: php -v Some scripts and extensions may only work with certain PHP versions. Before switching, make sure that all the scripts and extensions you are using support the new version. Otherwise, the website may become inaccessible or malfunction. Troubleshooting If PHP scripts are not being processed on your server, the first thing to check is the web server's functionality. Open a browser and go to the website where PHP scripts are not working. If the page opens but the PHP script output is not displayed, the problem may lie with PHP. Here are some steps you can take to troubleshoot the issue. Check PHP Service Status Run the following command, using your PHP version (e.g., PHP 8.3): sudo service php8.3-fpm status If the service is running, the output should indicate active (running). If the service is not running, start it with this command: sudo service php8.3-fpm start Check PHP Log Files To view PHP log files, use the following command: tail /var/log/php7\8.3-fpm.log This command will display the last few lines of the PHP log file, which may help identify the issue. Check PHP Configuration Open the php.ini file in a text editor and ensure the display_errors option is set to On. This will allow PHP errors to be displayed on your website pages. Check for Script Errors Open the PHP scripts in a text editor and look for syntax errors or other issues that could prevent the scripts from working properly. Check for Web Server Restrictions Check the web server configuration for any restrictions that might affect the execution of PHP scripts. For example, there may be restrictions in the .htaccess file that prevent certain directories from running scripts. Test the Script on Another Server If the script works on another server, the issue may be related to the configuration of the current server.