How-To: Prevent SPAM with Apache’s mod security
WordPress is a great piece of software to run a blog, it is flexible, has tons of plugins are developed for it and updates are really easy to do. To fight sp...
system
How-To: Fight SPAM with Postfix RBL
Spam, spam everywhere! If you are hosting your own mail server, fighting spam can become tricky. Antispam solutions do catch a fair amount of them, but still...
How-To: using Python Virtual Environments
A nice thing about Python is that there is tons of modules available out there. Not all those modules are readily available for your distro and even if there...
How-To: Automatically logout idle bash session
It can be useful to have a bash session automatically closing after some time. One of the obvious reason you might want this to happen is to make sure that n...
How-To: WiFi roaming with wpa-supplicant
wpa_supplicant can be used as a roaming daemon so you can get your system to automatically connect to different network as you are going from one location to...
How-To: Make a file Immutable/Write protected
There might be time when you want to make sure that a file will be protected from accidental/automated change/deletion. While one can protect a file/director...
How-To: tail multiple files with multitail
Many times you will end up tailing multiple files simultaneously. There is a sweet linux utility called multitail that will let you tail multiple files at th...
How-To: Reboot on OOM
Ever had your linux box getting Out of Memory (OOM)? Cleaning up after the OOM killer kicked in to find out that even though OOM killer did a decent job at t...
How-To: find which program consumes your bandwidth with nethogs
Let’s continue the network monitoring serie with yet another use case…. the “What program is using my bandwidth?” problem while not imposible to solve, still...
How-To: monitor network bandwidth usage with vnstat
There is many tools out there that help in monitoring network usage, collect statistics and generate graphs so we can view what happened at a given date/time...
How-To: Bash Parameter Expansion and String Manipulation
Last time we saw how bash can help us in handling default values out of the box using parameter expansion. This time we will see how basic string operations ...
How-To: Bash Parameter Expansion and Default Values
Bash is a sh-compatible command language interpreter that executes commands read from the standard input or from a file. There is much more to bash than run...
Mastering Top
top is most likely one of the most known Linux command and also one of the most used one, however most people do not take full advantage of its capabilities.
How-To: OpenVPN on Debian Squeeze with Username/Password authentication
OpenVPN is a SSL based VPN software that runs on most OS. It is simple to install and run.
How-To: Running Munin 2.0 on Debian Squeeze (6.0)
Munin 2.0 has been released and a .deb package has even been backported to Debian Squeeze!.
How-To: Change boot runlevel with Grub2
Linux start up behaviour is driven by the so-called runlevels. It will use the default value provided in /etc/inittab for some systems (Debian…), or /etc/ini...
How-To: Tmux a Terminal Multiplexer
As a sysadmin, most of my time is spent working on remote machines and different task. tmux is a terminal multiplexer, meaning it allows you to run multiple ...
How-To: Log HAProxy messages only once
When enabling logs with HAProxy on a busy web site, hard disk space can quickly become a scarce resource.
How-To: WMware Workstation 7.1 on Ubuntu Maverick Meerkat 10.10
There were some changes in the latest kernel release (2.6.34) that prevent VMware’s VMCI Socket module to compile on Ubuntu 10.10 (Maverick Meerkat).
How-To: Set up a L2TP over IPSec VPN using a Radius backend — page 3
In the previous part, we have configured XL2TP
How-To: Set up a L2TP over IPSec VPN using a Radius backend — page 2
We have now configured IPSec, let’s carry on with the next step.
How-To: Set up a L2TP over IPSec VPN using a Radius backend
Even though I pretty like OpenVPN, there is still some devices that might not support the TUN/TAP driver needed by OpenVPN.
How-To: Disable pulseaudio and sound in GDM
If like me you use MPD as a service daemon to listen to music, you might be annoyed anytime GDM start a pulseaudio process which prevents MPD from accessing ...
How-To: Mounting /dev in a chroot environment
When working in a chrooted environment, there is a few special file systems that needs to be mounted so all programs behave properly.
How-To: Network-Manager-OpenVPN overwrites default route
I was trying network-manager-openvpn plugin today on Lucid, I could import my configuration, DNS was set up correctly upon connection/disconnection, route im...
How-To: Rescan a SCSI bus without Rebooting
When you hotplug a hard drive in a virtual machine, the drive do not show in fdisk -l output until you reboot your VM.
How-To: Changing the default text editor
There is a few software that will use the editor command to find out what text editor to use. Example commands will be dch to add a new .deb changelog entry,...
Vmware Workstation: DNS not working with NAT
Lately, I have been experiencing a funny network issue when using VMware Workstation VMs with NAT interface. Roughly, the IP network was working fine, but DN...
How-To: Redirecting network traffic to a new IP using IPtables
While doing a server migration, it happens that some traffic still go to the old machine because the DNS servers are not yet synced or simply because some pe...
How-To: Bzr over ssh with no bzr server
Bazaar (bzr) is a distributed version control system (VCS) sponsored by Canonical and thus bzr is widely used by the Ubuntu community.
How-To: encrypted partitions over LVM with LUKS — page 3 — install and config
4. Installing the system
How-To: encrypted partitions over LVM with LUKS — page 2 — encrypting the partitions
3. Encrypting the partitions
How-To: encrypted partitions over LVM with LUKS
Even though new distros installers tend to support filesystem encryption out of the box, most of the time, it might be interesting to actually understand how...
How-To: Remote syslog logging on Debian and Ubuntu
syslogd is the Linux system logging utility that take care of filling up your files in /var/log when it is asked to.
How-To: Set up a LAN gateway with DHCP, Dynamic DNS and iptables on Debian Etch — page 4 — IPtables
We now provide IPs to the hosts in our LAN with our newly installed DHCP server. Now we need to pass their network packets around.
How-To: Set up a LAN gateway with DHCP, Dynamic DNS and iptables on Debian Etch — page 3 — DHCP server
Now that we have configured our DNS server, we need to distribute IPs to the machines in our LAN.
How-To: Set up a LAN gateway with DHCP, Dynamic DNS and iptables on Debian Etch — page 2 — DNS server
1. DNS server
How-To: Set up a LAN gateway with DHCP, Dynamic DNS and iptables on Debian Etch
Linux is a perfect platform to act as a router/gateway.
How-To: copy files over the network and preserve file permissions and informations with ssh and rsync
When copying files over the network, the files informations can be modified.
How-To: Intel Wireless 4965 AGN with Ad-Hoc network + WEP
The Intel wireless card 4965 AGN does not work properly on ad-hoc networks since hardy and kernel 2.6.24 or around, network-manager can’t get it to use the m...
How-To set up a serial console client
In the 2 previous articles, I explained how to set up a serial console on Ubuntu and Debian.
How-To set up a serial console on Debian
This tutorial will go over the steps to go through in order to set up a serial console on Debian Linux.
How-To set up a serial console on Ubuntu
This tutorial will go over the steps to go through in order to set up a serial console on Ubuntu Linux.
How-To: Import/Export GPG key pair
This tutorial will show how you can export and import a set of GPG keys from one computer to another. This way, you can sign/encrypt the same way one differ...
How-To: Customizing SSH client
SSH is great. There is so many thing you can do with it other than just a remote secure shell like X forwarding, port forwarding, authenticate using a privat...
How To: booting another Grub from Grub
Chainloading an operating system allows grub to boot an opearating system’s boot loader. This is commonly used to boot Windows for instance.
Terminator: A multi-view terminal
Terminator gives the possibility of having multiples terminal within the same window.
How-To: email notification upon available package updates with cron-apt
cron-apt is a tool run by a cron job at regular interval that will check for package updates and optionally do some actions.
How-To: getting VMware-server 2.0 beta MUI Remote Console to work with Firefox
Lately, I have been trying vmware-server 2.0 beta build 63231. It worked pretty well, but for the fact that the Remote Console to the VM was not working thro...
How-To: Customize your Ubuntu Live CD — page 2
We have now set up the base live cd, let’s make this live CD our own by customizing it.
How-To: Customize your Ubuntu Live CD
Live CD are great, they let you try out a distribution without installing it. They allow you to run your favorite distribution on any computer and on the top...
How-To: Find files on your computer with find
A standard Linux system has an incredible amount of files installed. Looking for a file location can be a painful task to do though a file browser.
How-To: Find missing packages with apt-file
apt-file is a command line tool for searching packages in Debian/Ubuntu repositories. Unlike apt-cache search, apt-file can find files in uninstalled or can...
How-to Create a Filesystem within another partition’s file
Filesystems are usually created on a partition. When all your hard drive is already partitioned, creating a new partition can become a pain and creating a ne...
How-To: create a self-signed certificate
This tutorial will explain how to create a self-signed certificate that you will be able to use with apache in order to provide ssl support.
How-To: Connect to a Cisco VPN with vpnc
This tutorial will show how-to connect to a Cisco VPN Concentrator using vpnc.
How-To: Install Ubuntu on LVM partitions
LVM (Logical Volume Manager) is a great piece of software which allow you to deal with Logical Volumes. Using LVM along with ext3 filesystem, you are allowed...
How-To: Managing services with update-rc.d
Linux services can be started, stopped and reloaded with the use of scripts stocked in /etc/init.d/.
How-To: Unattended Ubuntu Deployment over Network — page 5 — Preseed File
5. Preseed: Installation automation:
How-To: Unattended Ubuntu Deployment over Network — page 2 — DHCP server
For the purpose of this tutorial, I decided to choose dnsmasq to act as a DNS/DHCP server. The reason behind this is that dnsmasq is simple to configure and ...
How-To: Unattended Ubuntu Deployment over Network
there is many ways of installing Linux. Nowadays, the most common one is probably by using a CD. Download the CD, stick it in your CDRom drive and let’s roll...
How-To: Monitor your servers with SNMP and Cacti — page 3
3. Adding new devices to cacti
How-To: Monitor your servers with SNMP and Cacti — page 2
Now that we have our snmp server up and running, we are going to install cacti to manage the snmp server in our network.
How-To: Monitor your servers with SNMP and Cacti
SNMP (Simple Network Management Protocol) is a protocol for managing networks. Each managed entity in the network will run an snmp server (snmpd) which is go...
How-To: FTP Virtual Host with ProFTPD and MySQL — page 2
4. Configure ProFTPd
How-To: FTP Virtual Host with ProFTPD and MySQL
Using ProFTPD and its SQL module for MySQL, it is possible to give FTP access to non system users.
How-To create a MySQL database and set privileges to a user
MySQL is a widely spread SQL database management system mainly used on LAMP (Linux/Apache/MySQL/PHP) projects.
How-to: VMware-server – VMware-workstation 5.5 under Ubuntu Feisty
Since Ubuntu 7.04, Feisty Fawn, Ubuntu is using a standard kernel 2.6.20. Because of a few changes in the API, VMware-server and VMware-workstation 5.5 fail ...
Awstats: Error: Couldn’t open server log file … logresolvemerge.pl … access.log …. No such file or directory
After an upgrade from Debian 3.1 (sarge) to Debian 4.0 (etch), awstats stopped automatically updating.
How-To: Recover root password under linux with single user mode
It happens sometime that you can’t remember root password. On Linux, recovering root password can be done by booting Linux under a specific mode: single user...
How-to: Installing Ubuntu Linux on a usb pendrive — page 2
3. Installing Ubuntu on the USB stick
How-to: Installing Ubuntu Linux on a usb pendrive
This tutorial will show how-to install Ubuntu on a usb stick. Even though this tutorial uses Ubuntu as its base distribution, you could virtually use any typ...
How-To set up a LDAP server and its clients — page 2
2. Configuring the clients
How-To set up a LDAP server and its clients
LDAP (Lightweight Directory Access Protocol) allows central user, group, domain….. authentication, information storage …
How-To turn off beep from virtual console
Linux offers a great tool: Tab Completion. With tab completion, you can easily navigate through your filesystem, find command names you forgot the exact name...
How-to get your removable device mounted under an explicit and persistent name
You might have wondered how comes that your mp3 player is automatically mounted under a nice name like JUKEBOX for instance, while you usb stick simply get a...