Optimize MySQL Performance with Mysqltuner

MySQL Optimization

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

How to block access to a server by IP address on Linux

Block access using route command

Sometimes you might want to block connects to your server by IP address. E.g. when someone tries to attack your system. This can be done in several different ways, e.g. with iptables (firewall) rules or by setting up a reject route. Reject access with Linux route command Using iptables sometimes causes conflicts with installed firewalls ... Read more

[Solved] MySQL: Too many connections error

This guide shows you how to solve the error message "Connect to MySQL server 127.0.0.1: Too many connections". The error can appear in any log file of a service that connects to the MySQL server. This may e.g. be the /var/log/mail.log file if your email system uses a MySQL database. The error means that the ... Read more

How to reset the MySQL root password

mySQL root password reset

The following steps describe the procedure to reset the MySQL root password on Linux. The same procedure works for MariaDB too. 1) Stop the MySQL server service mysql stop 2) Start the MySQL server manually without permission tables which allows us to login as root user without password: mysqld_safe --skip-grant-tables & 3) Login into MySQL ... Read more

How to redirect an HTTP connection to HTTPS in Apache webserver

HTTP to HTTPS

HTTP connections can be redirected to HTTPS using the apache mod_rewrite module. Mod_rewrite should be available in every apache installation. Apache HTTP to HTTPS Redirect Create a file with the name .htaccess in the website root directory which contains the following lines: RewriteEngine On RewriteCond %{HTTPS} off RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} If you use ISPConfig 3, ... Read more

Redirect a subdomain in Apache and keep the URL in the address bar

Apache Redirect

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

How to access a name based website without a DNS record

Hosts file

If you want to access a name-based website that you created e.g. in ISPConfig before the DNS records are set up, edit the hosts file on your workstation computer and add a line like this: 192.168.0.100        www.mydomain.com mydomain.com Edit hosts file on macOS X To edit the hosts file on a computer running macOS X, ... Read more

[Solved] Postfix: “queue file write error”

Postfix: Queue File Write Error

If you get an error like: Apr 15 12:41:03 webb4 postfix/sendmail[11234]: fatal: web1_user(12967): queue file write error in your mail log, then the value for message_size_limit in postfix main.cf is too low. Solve Postfix queue file write error Edit postfix main.cf: nano /etc/postfix/main.cf and set the message size limit to a higher value. E.g. message_size_limit ... Read more

How to speed up logins in pure-ftpd on Debian or Ubuntu Linux by disabling name resolution

PureFTPD DontResolve

If you experience problems with slow logins in pure-ftpd, this is often caused by a problem with the resolving of the client's hostname. This happens e.g. when you run an FTP server in your intranet and the hostname of the client computer does not exist in DNS. Disable PureFTPD name resolver To disable name resolving ... Read more