High-End Linux Consulting and Security

System Administration

Services
SLES (Novell Suse Linux Enterprise Server)
GPFS (IBM General Parallel File System)
Nagios and Cacti
Apache hardening
IDS/IPS systems with Snort
Training

Instant work relief
100% knowledge transfer
Low administration effort

Locations
I work in all English and German-speaking Countries. There is no time limit.

Next availability
February 1st 2011


Qualification and experience

I have studied computer science in Germany. My degree is "Diplom-Informatiker(FH)" which is between bachelor and master. Additionally I am certified as a Novell CLP and CLE 10.

I have more than five years experience in professional Linux system administration.
Some of the companies I worked with:
* DB Systel GmbH
* AVL Deutschland GmbH
* Deutsche Bausparkasse Badenia AG
* Fox Mobile Distribution GmbH
* 1&1 Internet AG

Latest Linux Videos


Nagios: how to find help and detailed information to a Nagios check



Nagios: how to remove all comments of a single host at once



Nagios: how to cancel a scheduled downtime for a single host

Linux Notepad

Linux Tutorials

Nagios video tutorials

Desktop videos with sound

Sorting according to status in Nagios 3.2.1

OCP daemon increases Nagios performance in distributed setups

Operations on Nagios host groups

Nagios 3 with failover on SLES 11 with NConf, NRPE, NSCA, PNP4Nagios and NagVis

RPM packages for NRPE

Import single database from MySQL dump

Channel bonding on SLES 10

The Weathermap Plugin of Cacti

The Discovery Plugin of Cacti

Investigation of hacked Linux Servers

Cacti Tips

snmpd binds to 127.0.0.1 only

Examples of SNMP requests

Delete a Gnome session

Change the language in Gnome

My favorite Linux books

Examples of common SELinux commands

How to make SELinux log to a seperate file

Tell SELinux to NOT log only once in permissive mode

SELinux newrole Couldn't get default type

Print the whole command line of processes with ps

How to run two independent MySQL daemons on the same server

How to burn a DVD image with growisofs and verify it

How to run two instances of sshd on Debian

mdadm error No mail address or alert command - not monitoring

How to find processes associated with open ports

How to search in the bash history

Configure Postfix as a relay client

Nagios notification commands and Postfix sendmail

NaNs in Cacti/Spine

Bash scripts for text file manipulations

PHP scripts and HTTP error 500

vBulletin installation with UTF-8

Full backup of web servers with MySQL databases

Linux Server Hardening

Nagios 3 installation tutorial for Gentoo

How to test SNORT

Use dhcpcd on the shell to retrieve an IP address via DHCP

How to change the file permissions with chmod and chown

Replace SSH login with public key authentication

A compromised web server from the hackers point of view

More security for Apache web servers with mod_security

Some tips to find out if a web server was hacked

Where do answers and solutions come from?

The monitoring server tutorial with Nagios 2.8, NRPE 2.7.1 and Fruity

Secure settings for PHP web applications in php.ini

Configure syslog-ng to store firewall logs in a separate log file

Example telnet ESMTP session with SMTP AUTH

Basic commands and tips for the text editor Vim

How to paste text into VIM with correct text indention

Mysql commands

The command mysqldump

Environment variables

How to validate a Google Sitemap

The command iptables

Running MySQL queries from a shell script or from the command line

How to create IP aliases on Linux

Gentoo configuration management with Cfengine and Subversion

How to set up a Postfix mail server with MySQL backend on Gentoo

How to rewrite the sender address in Postfix

Setting up a load balancing cluster with director failover based on Keepalived, LVS and Gentoo

Burn CDs and DVDs from the command line

Encrypting and decrypting files with GnuPG

Use screen to return to a session on a remote server even if the connection has been closed

How to configure grub for several linux installations on one hard drive

Use Allrights to backup and restore file permissions suid sgid sticky bits owners and groups

Check scripts written in Perl for the Nagios plug-in NRPE

How to create cronjobs

The command awk

The command sed

How to handle unusual file or directory names

How to use fdisk within a shell script

For loops as one-liners and within shell scripts

Control permissions of new files and directories with umask

Merging text files with a simple Perl script

Block SSH login attempts with denyhosts

How to send a message to other logged in users

Get a nice directory overview in the shell with tree

Display and set Linux kernel parameters with sysctl

The if statement in bash scripts and as a oneliner

Simple load testing of the Apache2 webserver with ab2

Create large files with random content

How to disable a Linux user account

Process examination with strace

Detecting all hosts in a network which are online

Gentoo Port for the nagios-plugins package modified for vservers

Simple example to collect system activity information with sysstat

rdate is a simple way to synchronize a hosts system time

Rotating log files which are being held by an open file descriptor

How to change the scheduling priority of CGIs

Web frontend for Apache .htaccess files

Measure the execution time of commands

Retrieve DNS information with dig

A simple web user agent in Perl

Whitelist patch for qmail ra-plugin rblchecks

How to find out the current shell type

If a root-server cannot boot the rescue system anymore

How to redirect stdin, stdout, stderr and use simple interprocess communication

Creating .htpasswd and .htaccess files from the command line

Create a nice greeting for the ssh login

Parallel execution of shell commands on several servers with DSH

How to change root within a shell script with chroot

Getting lots of information about files and file systems with stat

Gentoo tips and tricks

The internal field separator IFS

Turning off the tab-completion bell

The command split

The command cut

The command hdparm

The command tr

Perl example to get the calendar week

Use Whoisonline to analyse your web server traffic

Use Getmails to extract email addresses from Postcard Direct log files and other text files

How to find the name of the linux distribution

Use basename to get the filename from a path

The command cal

The command date

The command tar

The command find

The command grep

The command cp

The command nl

The command procinfo

The command pkill

The command pgrep

The commands kill and jobs

The command fuser

The command pstree

The command pidof

The command top

The command replace

The command chkconfig

The command xinetd

The command ifconfig

The command du

The command df

The command diff

The command scp

The command ssh

The command whereis

The command watch

The commands mount and unmount

The command cancel

The command lpstat

The command lp

The command wc

The command touch

The command rm

The command exit

The command chroot

The command uname

The command runlevel

The command su

The command finger

The command whoami

Show logins with the command last

The command w

The command passwd

The commands clear and reset

The command hostname

The command file

The commands unset and set

The commands modprobe and lsmod

The command recode

The command tail

The command head

The command pwd

The command pmap

The command wget

The command ls

The commands man and info