If the version of a PostgreSQL server changes, it is required to upgrade the version manually. This can e.g. happen, if you do a release upgrade of your Linux distribution. The below description explains how to use PostgreSQL pg_upgradecluster to upgrade PostgreSQL 9.6 from Debian Stretch (Debian 9) to PostgreSQL 11 of Debian Buster (Debian 10).Continue reading “PostgreSQL pg_upgradecluster”
PGModeler (http://www.pgmodeler.com.br) is a nice tool to design your (PostgreSQL) database. It supports import from and export to a databases. Ubuntu 15.10 comes with a quite recent version but e.g. Debian does not provide it in the repository. In this post I explain howto build the application on Linux (tested on Debian 8) from source.
A VirtualBox image needs to be shrinked again from time to time. Due to usage, updates, testing the size of the VDI files grows. The following post shows how to shrinken the VDI files again.
In the next part of the series, the protection of webservers is explained. In this example I use Apache HTTPd webserver. Similar configurations are also available for e.g. nginx. There are various reasons for protecting the webserver itself (webapplications installed will be described in on of the next posts). Attackers are e.g. scanning the server for vulnariblties or try to attack the server using invalid input.
As the next part of the series, the protection of the most common service SSH is described in this post. Almost every Linux based server will run a version of ssh daemon to be able to login from remote. In this post I will describe how to protect ssh using fail2ban.
After setting up fail2ban its time to check which ports are open. Potentially each open port should be protected using fail2ban.
Fail2ban helps a lot to get rid of unwanted traffic to your server which cleans your log files a lot. In this post I will describe how to setup fail2ban on your server.
Using fail2ban it is easy to ban unwanted users from your servers by denying access to it using the local firewall capabilities.