You are most likely using Netfilter, aka IPTables, if you are running a recent Linux distro. Most firewalls supplied with hosting control panels or simple setup scripts fail to take advantage of some of the more advanced features available. A feature…
Category: Using Linux
Reclaim reserved disk space XEN/KVM/VMWare/Dedicated
Joe Dougherty from SecureDragon.net (great guy running a great company) sent me a tip about this thread over at Lowendtalk.com and asked if I could write something about this “weird trick”. Actually it’s not a wierd trick, it’s a built in security…
Find your Debian version, the command line way
Like every VPS addict it is quite normal to forget which version of an operating system you are running especially if it is a server that you haven’t logged onto for a long time. In other cases, you may simply be…
Create a private/public key pair using PUTTYgen
Introduction This guide describes how to generate and use a private/public key pair to log in to a remote system with SSH using PuTTY. Using key-based SSH logins, you can disable the normal username/password login procedure which means that only…
Keep track of /etc with Etckeeper
You can insure yourself against accidentally changing your files using versioning. The technique can be used in many contexts, a good example that we will discuss below is the important configuration files for Linux Systems. Some programs have relatively small…
Add Users to the Sudoers List
When connecting to your VPS, you should never login as root, in fact, root logins with password authentication should be disabled. Instead you should mainly use a none-root account and elevate your access rights to root only when needed. By…
Quickinfo: Difference between OpenVZ and KVM
Since this question surfaces from time to time, here is a short description of the main difference between OpenVZ and KVM. Basicly it is two different ways to offer virtualization, OpenVZ using shared resources and KVM using full virtualization. This…
Command: network related commands
If you want to be the master of your VPS or dedicated server you must know some basic networking commands to troubleshoot connection issues or to find out more information about your or someone else server. This guide will not…
ipv6 tool in your Firefox browser
I got a tip about this firefox plugin the other day and it is one of these “nice to have” plugins. It will show the IP address(es) of the current page in the status bar, the IP will be red…
Command: Locate empty files and directories
When installing software on your VPS you will end up with both empty files and empty directories, often these are used as placeholders/lock files/socket files for communication. This short guide will give you some examples on how to find those…