Virtualbox init script to start/stop virtual machines

Given that your Virtualbox home folder is /virtualbox, you can use the following script to start/stop all machines at once: #!/bin/bash test -x /usr/bin/VBoxManage || exit 0 for i in `ls /virtualbox/Machines/` do case "$1" in   start)         echo -n "Starting Virtualbox-Image $i"         VBoxManage startvm $i -type vrdp         echo "."         ;; […]


Safely wipe your hard disk

If you're going to recycle or sell your old hard disk, it's recommended to wipe all your existing data before. On Linux to achieve this, you can use the command dd. The following command overwrites the whole disk with random values: dd if=/dev/urandom of=/dev/sdb Instead of /dev/sdb you have to put your drive.   Additionally […]


Installing a windows image on a Linux Virtualbox Host

In this case we're installing Windows XP. 1. First create the new virtual machine in Virtualbox: VBoxManage createvm -name "WinXP" -register   2. Now we assign at least 512MB RAM, activate ACPI and configure the first boot device to be the cd/dvd device of your host. The network is for terms of simplicity left to […]


Installing Virtualbox on Debian

1. wget https://www.virtualbox.org/download/oracle_vbox.asc 2. apt-key add oracle_vbox.asc   3. Now add the following line to to your /etc/apt/sources.list:     deb http://www.virtualbox.org/debian etch non-free     (replace etch with your release if using other)   4. apt-get update && apt-get install virtualbox     If using the .deb-Package from www.virtualbox.org/wiki/Downloads:   apt-get install bcc iasl xsltproc xalan libxalan110-dev uuid-dev zlib1g-dev […]


Virtual Vacation with Postfix and mySQL

There are several ways of creating auto-reply messages such as putting vacation files in to the user's home folders. This solution however is working completely with mySQL as backend. There is also a tutorial on this website which describes the installation of Postfix and MySQL, fitting together with this tutorial.   You firstly need the […]


DNS Load Balancing

There are different types of load balancing: One variant would be a software load balancer (for example ipvsadm), which would be running on an extra server, which would be between the webservers and the WAN. The load balancer in this case is controlling which request is fotwarded to which machine. I will describe this in […]


Installing 64bit flash player on Debian

If you're working with a 64Bit Debian Etch as your desktop, you'll surely have noticed that some features like the flash player browser plugin is not available in the 64Bit version.   To install the flash player on your 64Bit system, just modify your /etc/apt/sources.list by adding: # Multimedia Debianpakete deb http://www.debian-multimedia.org etch main deb-src http://www.debian-multimedia.org etch main # […]


Greylisting with Postfix

Greylisting is an effective method of reducing spam. There's a daemon called GLD which is quite easy to integrate into Postfix. If you do not have your Postfix installation running, checkout for my other howto's.   Installation of the needed package: apt-get install postfix-gld   For the service to really start, you need to modify the file /etc/default/gld and change […]


Realtime Blackhole Lists in Postfix

What are Realtime Blackhole Lists (RBL's)? RBL's are services that are keeping track of IP addresses from which spam or malware has been received. Cross-checking your incoming mails with one or more services may reduce your spam.   Some known example RBL's: sbl-xbl.spamhaus.org bl.spamcop.net More can be found here: spamlinks.net/filter-dnsbl-lists.htm     These RBL's can be […]


Blocking Hosts based on a mysql table in Postfix

Using Postfix you sometimes would like to have your own list of hosts / IP addresses that you wish to block – to prevent them spamming your servers for example. As with Postfix you can use mysql as backend, you can use a mysql table to store this list in. First of all we add the […]