Running a nightly backup script on a server system, such as a web hosting server, can result in a heavy load and longer latency for other processes, for example, HTML or .php pages load slowly during the backup because the backup script requires too many I/O or CPU resources. On Linux systems, two shell utilities ... Read more
In this short article, I explain how to disable IPv6 in the Debian 10 network stack. Why would one want to do this? Most likely if you have connection problems and cannot reach servers on the Internet from your Debian system using IPv6, while it works using IPv4. Disabling IPv6 should always be the last ... Read more
The following command can be used to check and repair all MySQL databases on a Ubuntu or Debian Linux System. I've tested the commands on Ubuntu 20.04 and Debian 10. Repair MySQL databases on Ubuntu Linux sudo mysqlcheck --defaults-file=/etc/mysql/debian.cnf --auto-repair --optimize --all-databases MySQL database repair on Debian mysqlcheck --defaults-file=/etc/mysql/debian.cnf --auto-repair --optimize --all-databases The benefit of ... Read more
Some internet access providers have port 25 disabled in their routers to prevent spam. If you run your own email server in a data center, you might have to enable the submission port (587) in postfix to be able to send emails from your local email client to your own mail server. Enable Submission Port ... Read more
This short tutorial describes the steps to optimize the performance of a MySQL database with the mysqltuner script. This tool can be used for MySQL and MariaDB. Install mysqltuner The mysqltuner High-Performance MySQL Tuning Script is available as a package on Debian 10 and Ubuntu 20.04, install it with at: sudo apt install mysqltuner For ... Read more
This short guide shows you how to get a list of all installed Packages on Debian Linux. Packages on Debian get installed with the apt package installer. We will use the dpkg command, which is part of the apt toolset, to query the installed packages database. Get all installed Debian packages dpkg --get-selections As you ... Read more
Jailkit is an easy-to-use tool to create and maintain jail environments for shell users on Linux. In this guide, I will show you how to move PHP and its dependencies into the jail so that the jailed user can execute PHP scripts inside the jail on an ISPConfig server. Edit the jailkit .ini file and ... Read more
This tutorial shows you how to solve the RoundCube webmail error message: config.inc.php was not found. on an ISPConfig Debian server that uses Nginx as the web server. Solution RoundCube webmail is accessed on an ISPConfig Nginx web server through the apps vhost. The PHP-FPM of the apps vhost is running under the user and group ... Read more
This tutorial shows you how to use redirect rules in the Apache web server. If you want to redirect a subdomain like sub.domain.tld into a subdirectory of the website and keep the original URL in the browser location bar, you may use the following apache directive. RewriteEngine on RewriteCond %{HTTP_HOST} ^sub.domain.tld [NC] RewriteRule ^/(.*)$ /sub/$1 ... Read more
There is no simple 'tolower' command on the bash, but you can convert uppercase characters to lowercase with a little shell script. The script uses the tr command internally for converting the chars. Create a shell script with the name 'tolower' that converts all text that is given as a command-line argument to lower case: ... Read more