Click on the arrow icon beside each category to display or hide all items within the chosen category. Summaries of each page may be hidden or shown by clicking the plus icon next each item. Use the Options menu to expand or contract all items, display or hide summaries or sort the table of contents.
- Blog Posts:
- Category: CLI Tricks (12)
- Adding Google Contacts to Roundcube Webmail
This article describes the necessary steps to integrate one's Google-based address book to the Roundcube web-based IMAP client. For people who tend to keep the…
- Adjust Keyboard Console Layout for Ubuntu 10.10
In order to temporarily change the keyboard layout of an Ubuntu system, the following command from package kbd (aptitude install kbd) does the trick: loadkeys {…
- Adjust the Number of Loop Devices
If you work intensively with virtualisation, vpns and other stuff that makes use of loopback-devices, the default number of 8 in distros like Debian and Ubuntu …
- AWK: The Linux Administrators' Wisdom Kit
Disclaimer: This article is written by Emmett Dulaney and published at http://crashrecovery.org/dulaney_awk.html. All credits on this article go to Emmett Dulan…
- Fix a degraded MD Array
Fix a degraded array (example): mdadm --re-add /dev/md0 /dev/sdb2
- OpenSSL Telnet Check
As an example: openssl s_client -connect imap.gmx.de:993 -quiet
- Regex Introduction
Disclaimer: This article is written by Lara Hopley and Jo van Schalkwyk and published at http://www.anaesthetist.com/mnm/perl/regex.htm. All credits on this art…
- Resetting the MySQL root password the dirty way
It happens to me quite often that I forget the root password of a MySQL-setup. In that case, a dirty way to reset the root user's password is to stop the databa…
- Simple activation of SSL for Apache2 in Ubuntu 10.10
Just a few simple steps are necessary in order to activate ssl on apache-daemon in Ubuntu 10.10: Load module: a2enmod ssl Activate ssl site config: a2ensite def…
- Tar Cheat Sheet
Tar Segmentation With today's increased flash storage sizes, there may not be many occasions where you need to split files. However, when you do need to do so, …
- Testing webserver-security with Nikto
A decent tool to test a webserver's security setup is Nikto. It performs comprehensive tests on any given webserver and outputs its vulnerabilities. Using Ubunt…
- Transmission daemon: remove finished torrents
In transmission-daemon, downloaded torrents stay listed as long as they are not manually removed. In order to get them flushed automatically, the following comm…
- Adding Google Contacts to Roundcube Webmail
- Category: LaTeX (2)
- Adjust texmf-Path in OS X
This tip describes how to adjust the storage location of the texmf-path in a Macports LaTeX installation. The following file needs adjustments accordingly: vi /…
- pdf-Tricks in Linux with pdftk
pdftk is a very useful and powerful pdf-toolkit. It is available for Ubuntu with the package pdftk. Here are some practical example if its usage. Merge Two or…
- Adjust texmf-Path in OS X
- Category: Linux (69)
- Adding Google Contacts to Roundcube Webmail
This article describes the necessary steps to integrate one's Google-based address book to the Roundcube web-based IMAP client. For people who tend to keep the…
- Adjust Cacti for fine grained Input Data
Cacti is a fine graphing solution for all sorts of use cases. It only has problems with with small range inputs. The result are graphs which lack labels, i.e. b…
- Adjust Keyboard Console Layout for Ubuntu 10.10
In order to temporarily change the keyboard layout of an Ubuntu system, the following command from package kbd (aptitude install kbd) does the trick: loadkeys {…
- Adjust the Number of Loop Devices
If you work intensively with virtualisation, vpns and other stuff that makes use of loopback-devices, the default number of 8 in distros like Debian and Ubuntu …
- Asterisk: easily forward Sipgate-calls while keeping the caller-id
This article describes how to forward phone calls that are incoming on a Sipgate VoIP-based number to any given mobile or landline in an affordable way by using…
- AWK: The Linux Administrators' Wisdom Kit
Disclaimer: This article is written by Emmett Dulaney and published at http://crashrecovery.org/dulaney_awk.html. All credits on this article go to Emmett Dulan…
- Bootstraping an Intel Atom-based Synology NAS
A SoHo-NAS is a handy device that can store loads of data and acts a central home server all at once. Just recently I had the chance to play around with one of …
- Cleanup Docker Containers
In order to cleanup docker containers from time to time just fire the following: docker system prune -a
- Configure German Spamassassin Update Channel in Ubuntu
Spamassassin already ships with the nice feature of running automatic updates to its core rules by using sa-update. Customisation of this update process is not …
- Configure Spamassassin for Exim 4 in Ubuntu
*: Mail Transfer Agent This article describes the configuration of the spam scanner called spamassassin in conjunction with the MTA called Exim 4 in Ubuntu Linu…
- Create Meetme Conferences in Asterisk 1.8 (Ubuntu 11.10)
In order to mix different sound channels, the Asterisk MeetMe-extension relies on the dahdi-Module that take care of the necessary timing. This module is not a …
- Detailed Hardware Info
Details on a machine's hardware can be printed by using lshw. So information on the bus is collected by: lshw -businfo In order to trigger a detailed memory, th…
- Disable Multiarch in Ubuntu Oneiric 11.10
Since Ubuntu 11.10 multiarch support becomes set by default in new systems as well as in upgraded ones. This sounds like a nice feature, but it breaks one of my…
- Diskless Boot a Linux System (Debian)
In order to boot a Linux system disklessly from a server on your local network, these steps outline the necessary steps. Beware that this is just a brain dump.…
- Enable ActiveSync push for Cyrus IMAP-Servers using z-push
*: The IDLE feature allows IMAP e-mail users to immediately receive any mailbox changes. Regular desktop mail clients support push notifications when communica…
- Enable SMTP for PHP on Ubuntu
Many php-based web application are using php's smtp function. Unfortunately, Ubuntu's php default setup disregards the installation of packages necessary for us…
- Enabling ModSecurity protection in Apache2 on Ubuntu
This post documents how to add ModSecurity protection in Ubuntu's Apache. It has been tested on Ubuntu 11.04 but might work on earlier or latter issues with fe…
- Exim 4 and ClamAV Malware Scanning in Ubuntu
*: Mail Transfer Agent Although virus scanners are installed on virtually all regular client systems nowadays, it's nice to have the mailserver pre-scanning mai…
- Fix a degraded MD Array
Fix a degraded array (example): mdadm --re-add /dev/md0 /dev/sdb2
- Fix for unreadable File System of OpenWrt
If the OpenWrt system reports an unreadable file system try the following: mtd unlock rootfs_data
- FlexGet Installation in Ubuntu
*: Python Package Index This post is deprecated. Please go to http://www.grosseosterhues.com/2012/02/flexget-installation-and-upgrade/ for more recent informati…
- GnuDIP setup on Ubuntu 10.10
*: GNU Dynamic IP Introduction This article briefly describes the setup of a dynamic dns-server, very similar to those commercial ones from dyndns.org and oth…
- GPG secured Backups
There are some situations in which it becomes useful to store important and crucial data in non-trustworthy environments. One example can be an off-site backup…
- Greylisting in Exim 4 with Greylistd on Ubuntu Linux
*: Mail Transfer Agent In this article the approach of greylisting as a protection against spam in Exim 4 is being described. The concepts of greylisting tempor…
- Hardening PHP on Ubuntu with Suhosin patches
This post documents how to enable the Suhosin protection system for PHP on Ubuntu installations. It has been tested on Ubuntu 11.04 but might work on earlier or…
- Insight on MX-Entries
Recently, I gained some insight on the intended nature and its implications of the interaction of DNS with mail services. It seamed that rather suddenly, my mai…
- Install a new Drive with LUKS Disk Encryption
*: Linux Unified Key Setup This article describes the process of setting up a physical drive with LUKS encrypted filesystem. The process is tested on Ubuntu 10…
- Install Openmailadmin for Cyrus 2.2 in Ubuntu 10.10
: Sieve: filtering language : IMAP management frontend : Immediate notification of users about any mailbox changes : IMAP: Internet message access protocol : R…
- Install Transmission in Ubuntu 10.10 from PPA
This article explains installation of most recent Transmission versions into Ubuntu 10.10. Ubuntu's Personal Package Archive (https://launchpad.net/ubuntu/+ppa…
- Installation of Mailman in Ubuntu
*: Mail Transfer Agent Mailman is a powerful mailing list manager. It has a decent web interface for users and admins and offers content filtering, archiving, …
- KVM: Migrate from qcow2 to raw Format
The qcow2 disk format has some decent features like encryption, compression and -- as its abbreviation indicates -- copy to write support. Yet, its growing size…
- Linux Stress Tests
Several aspects of a Linux system may need a stress test at some point. To test the whole system: stress --cpu 16 --io 16 --vm 16 --hdd 16 --timeout 3600 To tes…
- Make snmpd's log more silently
A default snmpd log a bit too much for my taste. Therefore, /etc/default/snmpd can be adjusted. Change the following line from: SNMPDOPTS='-Lsd -Lf /dev/null -u…
- Migrate IMAP Accounts from one Server to another
There is a easy to use tool that facilitates the quick'n dirty move of the content of one IMAP account to a new server. Its name is imapsync. In Ubuntu, you may…
- Migrate KVM Disk Access from IDE to Virtio
This article assumes a KVM guest that runs from raw or qcow2 devices using emulated ide access. Since some time now, full virtualisation for block devices is av…
- Move Cacti data from one platform to another one
In order to migrate Cacti's rrd-tool data from one system to a different one, that data has to be converted to XML-format first. That is also true if you move f…
- OpenSSL Telnet Check
As an example: openssl s_client -connect imap.gmx.de:993 -quiet
- OpenWrt System Upgrade
There are two ways of easily upgrading an OpenWrt system. The old and nowadays deprecated way is: mtd -r write linux Newer versions (I assume version > back…
- pdf-Tricks in Linux with pdftk
pdftk is a very useful and powerful pdf-toolkit. It is available for Ubuntu with the package pdftk. Here are some practical example if its usage. Merge Two or…
- Prepping Ubuntu 10.10 for easy KVM-Setup
These are just the basic preparatory steps along with a list of necessary packages. Comprehensive howtos have to be found elsewhere. Fist, one needs to check if…
- Protecting an Asterisk server from brute force attacks with fail2ban
Recently, the server hosting my Asterisk setup started to get laggy and eventually it even died a few times on me. Checking the logs it turned out that unknown …
- Protection from unintended Reboots in Linux
Handling several servers in different concurrent ssh sessions can lead to confusion. This is explicitly dangerous when it comes to unintended reboots. Here, mol…
- Quick & Dirty VoIP Conference Room
This note describes the quick & dirty setup of an VoIP conference room using Astisk PBX and Sipgate. Three files have to be adjusted accordingly: sip.conf …
- Quick setup of Jabber-Server (ejabberd) in Ubuntu
This posts documents the necessary steps to setup a running Jabber-server in Ubuntu. It uses ejabberd v2.1.5 and by the time of writing it is tested on Ubuntu …
- Quickly setup a new Root Server at Hetzner's
Preparations in hetzner robot: Activate rescue-system Order automatic hardware reset Login into rescue system and change password Now, automatic setup can be…
- Regex Introduction
Disclaimer: This article is written by Lara Hopley and Jo van Schalkwyk and published at http://www.anaesthetist.com/mnm/perl/regex.htm. All credits on this art…
- Resetting the MySQL root password the dirty way
It happens to me quite often that I forget the root password of a MySQL-setup. In that case, a dirty way to reset the root user's password is to stop the databa…
- Resize KVM guest's raw volumes
After running virtual machines in KVM for some time, it might come in handy to be able to resize a KVM guest's raw volumes. In order to do so you first have to …
- Securing ssh Daemons from Brute-Force Attacks in Ubuntu
Install fail2ban: aptitude install fail2ban Create local configuration: cd /etc/fail2ban && cp jail.conf jail.local Edit /etc/fail2ban/jail.local …
- Settin up a custom Weave Sync Server for Firefox 4
Introduction Starting with Firefox 4 it is really easy to keep your different Firefox browser setups at home, on your mobile or at work in sync. The Mozilla Co…
- Setup Cyrus IMAP-Server on Ubuntu 10.10
: Sieve: filtering language : IMAP management frontend : Immediate notification of users about any mailbox changes : IMAP: Internet message access protocol : R…
- Setup of Roundcube Webmail 0.5.x on Ubuntu 10.10
: Sieve: filtering language : IMAP management frontend : Immediate notification of users about any mailbox changes : IMAP: Internet message access protocol : R…
- Setup of Sun Grid Engine
Sun Grid Engine facilitates computing in distributed computer networks. Its setup is just documented here. Its not nearly complete though. Setup log Enter the d…
- Setup squeezeslave on Intel Atom-based Synology NAS
Motivation It's a very decent feature in Syology's DSM 4.1 having Logitech Media Server at the tip of your finger as an official 3rd party package. It offers…
- Shutdown your hardware on temperature threshold
Faulty temperature control in a datacenter can cause terrible damage. In case you can't influence air con's reliability, you have to set up some protection on y…
- Simple activation of SSL for Apache2 in Ubuntu 10.10
Just a few simple steps are necessary in order to activate ssl on apache-daemon in Ubuntu 10.10: Load module: a2enmod ssl Activate ssl site config: a2ensite def…
- Squid 3.x config with NCSA Authentication in Ubuntu 16.04
Here comes an update to the old article on how to configure Squid. The new Squid 3.x which is available in Ubuntu 16.04 requires some different configuration. …
- Squid config with NCSA Authentication in Ubuntu 11.04
*: National Center for Supercomputing Applications This article is deprecated. For the recent version check the following article: https://www.grosseosterhues.c…
- Take over packagelist from one Debian to another
In order to sync the state of installed packages from one Debian or Ubuntu to another one, the following process can be helpful. Make a packagelist on the origi…
- Tar Cheat Sheet
Tar Segmentation With today's increased flash storage sizes, there may not be many occasions where you need to split files. However, when you do need to do so, …
- Testing webserver-security with Nikto
A decent tool to test a webserver's security setup is Nikto. It performs comprehensive tests on any given webserver and outputs its vulnerabilities. Using Ubunt…
- Transmission daemon: remove finished torrents
In transmission-daemon, downloaded torrents stay listed as long as they are not manually removed. In order to get them flushed automatically, the following comm…
- Ubuntu: configure general proxy usage
In order to let an Ubuntu system access the net via a proxy, edit two files and you're done. /etc/environment: http_proxy="http://:/" https_proxy="http://:/" ft…
- Ubuntu: enable MIBs in snmp tools
Lately I ran into some issues using snmp tools, e.g.: snmpwalk -v2c -c public ${host} test I received errors like: Unknown Object Identifier (Sub-id not found: …
- Unattended Security Updates in Ubuntu 10.10
In order to have automatic and unattended security updates in Ubuntu, one needs to install the according package: sudo aptitude install unattended-upgrades Due …
- Update '19: Get snmpd to log more silently
This is an update to the article from 2009 regarding quieting down snmpd - this time in recent Ubuntu LTS 18.04. The issue at hand is the intense chattyness of …
- Update: FlexGet Installation and Upgrade in Ubuntu
*: Python Package Index This is an update to my previous article on how to set up FlexGet in Ubuntu. In this post, FlexGet v.1.0r2733 will be used on Ubuntu 11.…
- Using Ipredator independantly from the default Route
This article is a copy of the howto from the Ubuntu forum by simonn (http://ubuntuforums.org/showthread.php?t=1472045). All credit go to him. I'm just copying …
- Using vmbuilder with libvirt
In order to use vmbuilder (in my case python-vm-builder 0.12.4) to generate fully functional Ubuntu kvm-images, the following adjustments to the libvirt-templat…
- Adding Google Contacts to Roundcube Webmail
- Category: OpenWrt (3)
- Fix for unreadable File System of OpenWrt
If the OpenWrt system reports an unreadable file system try the following: mtd unlock rootfs_data
- Fresh install of OpenWrt Backfire from Mac OS X 10.6 by tftp
This article documents flashing OpenWrt Backfire on Linksys WRT54g v2 and on Asus WL-500g Deluxe and Premium. It uses OS X's built-in tftp to transmit the firm…
- OpenWrt System Upgrade
There are two ways of easily upgrading an OpenWrt system. The old and nowadays deprecated way is: mtd -r write linux Newer versions (I assume version > back…
- Fix for unreadable File System of OpenWrt
- Category: OS X (16)
- Adjust texmf-Path in OS X
This tip describes how to adjust the storage location of the texmf-path in a Macports LaTeX installation. The following file needs adjustments accordingly: vi /…
- Disable Apple Ping
With iTunes 10 Apple introduced a new annoyance: Ping. It's a new music-centric social network, for which at least I don't have a use for. Therefore, the follow…
- Disable build-in iSight Camera in OS X up to 10.6
Paranoid people might dislike the glaring iSight camera in recent Apple computers. Apart from the option to put a sticker on the camera hole, the following scri…
- Disable creation of DS_Store files on network volumes
In order to keep OS X from creating DS_Store files on network shares enter the following command in Terminal's CLI: defaults write com.apple.desktopservices DSD…
- Flush OS X's DNS Cache
If you need to flush a Mac's DNS cache, the following line will be helpful: sudo dnscacheutil -flushcache
- Fresh install of OpenWrt Backfire from Mac OS X 10.6 by tftp
This article documents flashing OpenWrt Backfire on Linksys WRT54g v2 and on Asus WL-500g Deluxe and Premium. It uses OS X's built-in tftp to transmit the firm…
- Full restore from Time Capsule with account-authentication
This week the people at Apple released their new OS X-Version called "Lion" (10.7). Some interesting new highlights in terms of UI, backup and encryp…
- Hide Application from OS X's Dock
To hide an application from OS X's dock edit its plist-file and change the according lines to match the following: <key>LSUIElement</key> <string…
- Install Privoxy 3.0.12 on OS X
This is merely an install log which pretty much describes the basic setup and maintenance work in itself: $ sudo port install privoxy Password: ---> Computing …
- List Disks in OS X
A simple but useful command line to find out about hardware names of connected disks in OS X is: diskutil list
- OS X: disable Mission Control on top edge
In El Capitan Apple introduced a feature which opens Mission Cotrol as soon as you drag a window to the top edge of the screen. That is annoying at least to me.…
- Quick Screenshot in OS X
A very quick screenshot is taken and saved to your Desktop by the following keyboard shortcut: CMD+Shift+3
- Quick Traffic Shaping in OS X
In order to enable bandwidth limitations in OS X the following can be useful. This example limits port 139/tcp and port 445/tcp to 5 MBit/s: ipfw -f pipe flush …
- Reset a Mac's PRAM and NVRAM
In case you need to reset a Mac's PRAM and NVRAM, do the following steps: Shut down the computer. Locate the following keys on the keyboard: Command, Option, P…
- Sleep/Wake Events in OS X
*: http://www.macports.org/ In case you wish for certain events to take place on sleep or wake of you Mac, the software sleepwatcher is your friend. You can ins…
- Wifi Analysis in OS X
Aside from all those OS X wifi scanners originating from the Linux world, OS X comes with its own basic tool called airport. For quick access do the following: …
- Adjust texmf-Path in OS X
- Category: Security (10)
- Enabling ModSecurity protection in Apache2 on Ubuntu
This post documents how to add ModSecurity protection in Ubuntu's Apache. It has been tested on Ubuntu 11.04 but might work on earlier or latter issues with fe…
- GPG secured Backups
There are some situations in which it becomes useful to store important and crucial data in non-trustworthy environments. One example can be an off-site backup…
- Hardening PHP on Ubuntu with Suhosin patches
This post documents how to enable the Suhosin protection system for PHP on Ubuntu installations. It has been tested on Ubuntu 11.04 but might work on earlier or…
- OpenSSL Telnet Check
As an example: openssl s_client -connect imap.gmx.de:993 -quiet
- Protecting an Asterisk server from brute force attacks with fail2ban
Recently, the server hosting my Asterisk setup started to get laggy and eventually it even died a few times on me. Checking the logs it turned out that unknown …
- Protection from unintended Reboots in Linux
Handling several servers in different concurrent ssh sessions can lead to confusion. This is explicitly dangerous when it comes to unintended reboots. Here, mol…
- Securing ssh Daemons from Brute-Force Attacks in Ubuntu
Install fail2ban: aptitude install fail2ban Create local configuration: cd /etc/fail2ban && cp jail.conf jail.local Edit /etc/fail2ban/jail.local …
- Simple activation of SSL for Apache2 in Ubuntu 10.10
Just a few simple steps are necessary in order to activate ssl on apache-daemon in Ubuntu 10.10: Load module: a2enmod ssl Activate ssl site config: a2ensite def…
- Unattended Security Updates in Ubuntu 10.10
In order to have automatic and unattended security updates in Ubuntu, one needs to install the according package: sudo aptitude install unattended-upgrades Due …
- Wifi Analysis in OS X
Aside from all those OS X wifi scanners originating from the Linux world, OS X comes with its own basic tool called airport. For quick access do the following: …
- Enabling ModSecurity protection in Apache2 on Ubuntu
- Category: Synology (3)
- Adding bootstrap to Synology DSM
Use this guide as the previous how-to is not working anymore on DSM 7.x: https://github.com/Entware/Entware/wiki/Install-on-Synology-NAS In package center >…
- Bootstraping an Intel Atom-based Synology NAS
A SoHo-NAS is a handy device that can store loads of data and acts a central home server all at once. Just recently I had the chance to play around with one of …
- Setup squeezeslave on Intel Atom-based Synology NAS
Motivation It's a very decent feature in Syology's DSM 4.1 having Logitech Media Server at the tip of your finger as an official 3rd party package. It offers…
- Adding bootstrap to Synology DSM
- Category: Uncategorized (3)
- Brew Autoupdate
Run the following command to letbrew update itself automatically: brew install pinentry-mac brew autoupdate start 43200 --upgrade --cleanup --immediate --sudo
- Measuring Ubuntu boot performance
Measuring boot performance in Ubunu is fairly simple. Systemd provides a tool for that. The overall boot time for kernel and userspace is given by: systemd-anal…
- Ubuntu: clone installed packages to a new system
apt-clone: On the source system, do the following: apt-get install apt-clone apt-clone clone Copy \<systemname>.apt-clone.tar.gz to the new machine and run:…
- Brew Autoupdate
- Category: CLI Tricks (12)