Connecting to SSH via public keys

A secure way to connect to distant servers without using a password all the time is connecting via public keys. On the source system we first need to create the key pairs using: ssh-keygen -t rsa Then we copy this key to the destination server that we would like to connect to (change username to […]

Web Projects with Subversion

In this tutorial I'd like to show how you can setup subversion for your web projects. apt-get install subversion subversion-tools Now you create the svn repository – below I simply call it project, change it to fit your project name. I suggest to create the svn databases below /var/svn: mkdir /var/svn cd /var/svn svnadmin create […]

The file /etc/mtab explained

All mounted drives on your system with their options are listed in the file /etc/mtab. This file is automatically generated and updated. The options in the right order: Drive Mount point File system Options Dump Check An example: dev/sda2 / ext3 rw,errors=remount-ro 0 0 tmpfs /lib/init/rw tmpfs rw,nosuid,mode=0755 0 0 proc /proc proc rw,noexec,nosuid,nodev 0 […]

Gentoo: kernel installation with genkernel

The simpliest way t install a new kernel on a Gentoo machine, is to use genkernel. In case you don't have genkernel installed yet, you can do so by executing: emerge genkernel emerge gentoolkit The kernel sources can then be installed with: emerge gentoo-sources Usually can be found in /usr/src after the installation Now we're […]

PROCMAIL: E-Mail Zustellung per Procmail-Filter

Den Filter Procmail kann man auf zweilei Arten einbinden: Man kann die Datei /etc/procmailrc anlegen. Diese Datei gilt dann für alle Benutzer Man kann im home-Verzeichnis des jeweiligen Benutzers die Datei .procmailrc anlegen. Dann gelten die Regeln nur für den jeweiligen Benutzer. Am besten erklärt sich die Funktionsweise anhand eines Beispiels: MAILDIR=/var/spool/mail PATH=/usr/bin:/usr/local/bin SHELL=/bin/sh LOGABSTRACT=NO […]

Cyrus IMAPd mit mySQL – Installation

Vorbemerkung: Dieses Tutorial ist kombinierbar mit dem Postfix-Tutorial. Erforderliche apt-Pakete bei Debian: cyrus21-admin – Cyrus mail system (administration tool) cyrus21-clients – Cyrus mail system (test clients) cyrus21-common – Cyrus mail system (common files) libauthen-sasl-cyrus-perl – Perl extension for Cyrus SASL library libauthen-sasl-perl – Authen::SASL – SASL Authentication framework libsasl2-2 – Authentication abstraction library libsasl2-modules libsasl2-modules-sql […]

Debian: Installing/Updating your kernel

You can show the currently running kernel version by: uname -a There are 3 possibilities updating your kernel on Debian:   1. Installation of a kernel image: This is the simpliest way of installing a new kernel. If you have no special requirements or special stuff that you want to have in your kernel, this […]

Network Bonding

How can I increase the bandwidth of my server? How can I have network failover for my server? A good approach is to use BONDING. The following has been tested on Debian and Gentoo. For the whole thing to work, you need to activate the bonding kernel module: modprobe bonding Most kernels on current distributions […]

Gentoo: system and security updates

First install gentoolkit emerge gentoolkit Then search for security updates using glsa-check: glsa-check -t all Check which packets would be installed: glsa-check -p $(glsa-check -t all) Then run the actual installation glsa-check -f $(glsa-check -t all) Or install them one by one: glsa-check -f INSTALLNUM Replace INSTALLNUM by the update number, for example 200608-15 System […]

Creating a software raid using mdadm

Installation on Gentoo: emerge mdadm rc-update add mdadm default /etc/init.d/mdadm start Installation on Debian/Ubuntu: apt-get install mdadm Installation on RedHat/Fedora: yum install mdadm You can activate the kernel module by executing: modprobe raid1 First of all, we are going to create some nodes: mknod /dev/md1 b 9 1 mknod /dev/md2 b 9 2 mknod /dev/md3 […]