Here are the instructions on how to install an efficient Linux remote desktop (XCFE) using VNC. apt-get install xorg xfce4 xfce4-goodies vnc4server Note: If you want to change the initial VNC port edit the file: /usr/bin/vnc4server and change the port as follows: eg. to change the vnc ports to start at 8081 ‘$vncPort = 8080 …

Command: /usr/bin/clamscan -r -i /start/directory

Problem Description: Although it can happen very rarely sometimes the dpkg, run by apt-get or aptitude, gets confused and leaves the lock on the mounting of its database open after being terminated. This prevents any further operations on installing, updating or configuring packages. The error would look like this: debconf: DbDriver “config”: /var/cache/debconf/config.dat is locked …

Often when seeting-up a VPN or other similar mechanism we need to transfer securely a private key or a list of passwords or anything very private to another party via email without running the risks of the man-in-the-middle snoopin on it. Here is a method using OpenSSL which is available in Linux. Sending a one …

In order to find out where the domain resolving fails here are some tricks using the command dig to trace the recursion step by step till the DNS that fails to deliver the IP of the requested [sub]domain. Reference site: https://nsrc.org/workshops/2005/pre-SANOG-VI/bc/dns/dns2-02-dig-debug.html Tracing a well resolving domain: So first we start by asking one of the …

Task: Keep multiple web server’s htdocs files in sync. One way to do it is to write a script as cronjob which synchronizes the main server’s configuration directories to all other servers. But there are more elegant ways to do it: GlusterFS and lsyncd. This article relates to the later: lsyncd This deamon process uses …

I’ve got a project where we needed to make sure the user had to be authenticated against Windows Active Directory. This is what helped me. Install the LDAP tools: (Example in Debian) apt-get install ldap-utils Command to authenticate Note: the user(Username) registered in Active Directory DN(DC=ad,DC=domain,DC=net). (Return code of command should be 0 if successful) …

Sometimes I try to unmount a storage device and it says that it cannot unmount because a process is using it. Now how to find this/these processes and kill them so I can unmount the device? Here is one way to do it. Long and careful way, step by step: # Find out the mount …

In some situations if one needs to change the MAC address of an ethernet card here is the way: ifconfig eth0 down ifconfig eth0 hw ether [new mac address] ifconfig eht0 up ifconfig eth0 And see you brand new ethernet address. have fun hacking 🙂

Problem: Lately I had the problem that some users could not log-in into their webmail(Squirrelmail). Squirrelmail answered: “ERROR: Connection dropped by IMAP server”. Looking into the logs I found the following lines: Jul 5 10:39:43 ms41 dovecot: imap-login: Login: user=user1>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured Jul 5 10:39:43 ms41 dovecot: IMAP(user1): mail_location not set and autodetection …

Introduction: This HOW-TO will describe with very few explanations how to minimally configure Heartbeat software for the purpose of automatically switching a virtual IP from one server to another when the default server fails. Here a ‘Virtual IP’ will be switched from one server to another depending on which one is available. Install heartbeat: apt-get …

Here are simple steps on how to dist-upgrade a Debian system using an ISO file. Normally the process would be quite simple by replacing the entries in the repository list and call a command apt-get update; apt-get disp-upgrade. BUT what if your system doesn’t have Internet acccess while you want to do the upgrade? Here …

Distro URL Command ====== ======================== ============================ Debian (http://www.debian.org) apt-get install packagename Ubuntu (http://ubuntulinux.org) apt-get install packagename Suse (http://www.opensuse.org) yast -i packagename Fedora Core (http://fedoraproject.org) yum install packagename FreeBSD (http://www.freebsd.org) pkg_add -r packagename Gentoo (http://www.gentoo.org) emerge packagename OpenBSD (http://www.openbsd.org) pkg_add -r packagename

Introduction: Imagine you have rented a system at a provider where you want to install remotely a totally new Debian Squeeze from scratch. You will need the following components: – A Remote KVM Switch where you can view and control the system via a console remotely. – A knoppix or any relatively recent bootable live …

In the case we absolutely need to install a special Debian package, from backports for example, and force it to ignore dependencies using aptitude download and dpkg –force-depends, your apt-get and aptitude will always complain later on about it and not resume its given commands until we resolve this dependency. So when you know what …

This short how-to shows how to find out a string length in bash: Copied from the very useful web site: http://unstableme.blogspot.com/2008/03/find-string-length-bash.html Suppose: $ VAR=”Bash Scripting” Now to find the length of the above string, I have found 3 different ways: $ echo “${#VAR}” 14 $ expr length “$VAR” 14 $ echo $VAR | awk ‘{print …

Here is an example of how to compile and install the latest SVN system in Debian. At the time of writing the latest stable version was 1.6.17. Because this method contains all the dependencies of SVN compiling, it can probably be used in many types of Linux distributions. Here are only commands to run as …

Unfortunately as of today June 19, the repository drivers of Wireless Broadcom BCM4313(wl.ko) don’t work well at all in Linux Mint 11. After making some research on Google I found out that there are new Linux drivers provided by the manufacturer Broadcom that simply need to be downloaded and installed. I did it and it …

Although the Linux Kernel has already a load-balancing feature, it doesn’t come without the price of having to learn how to use it. Some tools like ‘LVS-KISS’ can help to do that job but still a bit too much sometimes when one want just crude load-balancing without any fall-back features. Here is a simple solution …

Sometimes we want to install a package that is in testing state into a stable system. To do so, just follow the instructions below. NOTE: The following tips have been copied from the link: http://forums.spry.com/debian/620-how-install-testing-packages-debian-stable-apt-get.html The solution for keeping stable and installing the package is to modify apt-get configuration to setup what is called a …

What a disaster to find that your File Allocation Table is been destroyed. Well there is a possible light at the end of the tunnel. Scenario: Partition to recover: /dev/sdb2 HOW-TO – Find out where the SuperBlock got backed-up with the command mke2fs -n This gives you all the locations where the SuperBlock is back-up …

NOTE: This article is a copy of the Geek Stuff Article at: 10 Useful Sar (Sysstat) Examples for UNIX / Linux Performance Monitoring Tanks for the tips. I have copied it to make sure this important article stays part of this tips collection. Intro: Using sar you can monitor performance of various Linux subsystems (CPU, …

These following instructions will download, compile and install Bacula and a couple of the best Web GUIs for it. Inspired from the following German link. Thank you: http://www.asconix.com/howtos/debian/bacula-backup-debian-lenny-howto Install needed packages for Bacula server aptitude install build-essential libpq-dev libncurses5-dev libssl-dev psmisc mysql-server libmysql++-dev Download compile and install Bacuda and its web GUI wget http://downloads.sourceforge.net/project/bacula/bacula/5.0.3/bacula-5.0.3.tar.gz tar …

I’m totally new to openERP . As I was looking for ways to install it on Debian Lenny I found multiple sites that have each their own way. Well then I decided to cook myself a mix of the methods used in all of those sites and here is the result which worked well: Note …

To disable permanently all low level kernel messages (iptables etc.) from flooding the console in Debian do the following changes: (you must be root for these changes) To make the changes permanent: Edit the file /etc/sysctl.conf add the following line: kernel.printk = 4 1 1 7 The above changes will be effective at reboot or …

Here are some useful sed commands. Note. The option ‘-i’ is making the changes directly into the file without having to send the result to a temporary file, and then replace the original with the temporary file. Very useful …. and dangerous. ———————————– Inserting a line of text at the beginning of the file Sometimes …

Sometimes we want to create a tarred directory but on a remote host. Here is the command. Example: To tar the whole /home directory to a tar.gz file on a remote server: (cd /home; tar cfz – .) |ssh {remote-host} dd of=/backup/filename.tar.gz obs=1024

Display the content of administrative text-based databases getent {ahosts|ahostsv4|ahostsv6|aliases|ethers|group|hosts|netgroup|network|spasswd|protocols|rpc services|shadow|gshadow} Generate secure passwords Install the tool apt-get install pwgen Generates a list of 8 char. passwords pwgen Generates 1 password of 10 char long pwgen 10 1 Get the filesystem type of a partition Get the filesystem type of /dev/sda2 file -sL /dev/sda2 Get the …

This is a copy of the following wonderful short and helpful site. Thanks. http://bashcurescancer.com/10-steps-to-beautiful-shell-scripts.html October 16th, 2007 Linux gurus don’t use cut, awk, and sed when they want to replace or strip out a portion if a variable. They use parameter substitution. You can learn parameter substitution in less than 2 minutes. Here is the …

USEFUL ONE-LINE SCRIPTS FOR SED (Unix stream editor) Dec. 29, 2005 Compiled by Eric Pement – pemente[at]northpark[dot]edu version 5.5 Latest version of this file (in English) is usually at: http://sed.sourceforge.net/sed1line.txt http://www.pement.org/sed/sed1line.txt This file will also available in other languages: Chinese – http://sed.sourceforge.net/sed1line_zh-CN.html Czech – http://sed.sourceforge.net/sed1line_cz.html Dutch – http://sed.sourceforge.net/sed1line_nl.html French – http://sed.sourceforge.net/sed1line_fr.html German – http://sed.sourceforge.net/sed1line_de.html Italian …

Each line inside /proc/diskstats is having the following info format: eg. for sda (Full disk) cat /proc/diskstats | grep ‘sda ‘ 8 0 sda 2461810 61427 148062742 6482992 660009 1544934 67900384 45642376 0 7162961 52128751 Meaning:(fields starting after the device name) Field 1 — # of reads issued Field 2 — # of reads merged …

After I installed Linux Mint 8 with ext4 filesystem on /, I happned to have to reinstall Windows which whipped out my grub Boot loader of Linux Mint 8 from MBR. So after I googled around I finally found a site that explains how to recover a grub2 from an installed Linux. In my case …

In the sender rsyslog configuration (/etc/rsyslog.conf) ——————————————— local0.* @syslog-server.com ——————————————— In the receiver rsyslog configuration (/etc/rsyslog.conf) Example: ——————————————— # provides UDP syslog reception $ModLoad imudp $UDPServerRun 514 $AllowedSender UDP, 127.0.0.1, 192.168.10.0/24 ———————————————