Knoppix is a Debian-based live cd which provides automatic hardware detection and a complete desktop solution.
LXDE is used as the default X11 environment.
It’s worth trying it as a rescue cd.
The lastest stable version is : 6.2.1

To download the English-spoken version :

EN Live Knoppix CD

Do not forget to verify the checksum of what you have just downloaded :

Knoppix v6.2.1 md5sum file

Let’s have a look at these following files as well :

The official README

The boot command line options

the list of all the packages included

To know if your CPU is 64 bit one, type the following command :

fool@localhost:~$ grep -w lm  /proc/cpuinfo

If you have an output like that containing the word lm, then you have 64 bit processor.

lm stands for Long mode which is only enabled for 64 bit CPU.

flags        : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm xsave lahf_lm tpr_shadow vnmi flexpriority
flags        : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm xsave lahf_lm tpr_shadow vnmi flexpriority

The command uname -i can provide the kind of hardware-platform on which your OS is running. However, you may have unkown as an output of uname -i.

In order not to type your passphrase everytime you connect to a server using ssh, put the code below in your own bashrc file :

SSHAGENT=/usr/bin/ssh-agent

SSHAGENTARGS=”-s”

if [ -z "$SSH_AUTH_SOCK" -a -x "$SSHAGENT" ]; then

eval `$SSHAGENT $SSHAGENTARGS`

trap “kill $SSH_AGENT_PID” 0

fi
Then reload your shell configuration by issuing the following command : source .bashrc

You will be asked to type once your passphrase and that’s it ! If you use keys-based authentication, do not forget to copy your public key to the servers you often connect to with the utility ssh-copy-id! ssh-agent will be very useful for you !

In order to make the connections to several servers through SSH easier, I use public/private keys-based authentication.

Cygwin provides all the basic tools related to SSH : ssh client, ssh-keygen, ssh-copy-id, ssh-add and ssh-agent.

Once I created my DSA keys with a passphrase, I sent my public key to all the involved servers with the ssh-copy-id utility.  So, each time I connect to a server, I only have to type my passphrase. It is possible to avoid it by using ssh-agent.

To start it : exec ssh-agent /usr/bin/bash

If you do not use exec, you will get the following error message :

Could not open a connection to your authentication agent

To add your DSA identity to your authentication agent : ssh-add ~/.ssh/id_dsa

Type your passphrase once and then, you will not need to type it anymore. You will be able to connect to servers where you have uploaded your public key.

This solution works only for your current xterm. If you open a new xterm session, you will have to type your passphrase.

To make sure that your system date always matchs the actual date, you need to install a ntp client
For Debian, just install ntpdate :

root@localhost:~#apt-get install ntpdate

To update your system date :

root@localhost:~#ntpdate 0.debian.pool.ntp.org

ntpdate provides two tools : ntpdate and ntpdate-debian. They do the same job except that ntpdate-debian reads the file /etc/default/ntpdate to look for ntp servers. ntpdate shoud only be used for occasional system date update.

If you work with a Debian Lenny, you may want to use a software whose version is more recent that the one available in the Lenny repositories.
This is easy if you use the Debian backports. These are special repositories which contain more recent softwares.
Let’s take an example with OpenOffice. There is a metapackage named openoffice.org which installs all the components of OpenOffice.org suite.
Here is the version available in Lenny repositories : 1:2.4.1
Here is the version available in the Lenny backports : 1:3.2.0-4

To get information about the versions available for the package openoffice.org :
fool@localhost:~$apt-cache policy openoffice.org

apt-cache policy openoffice.org
openoffice.org:
Installed: 1:3.2.0-4~bpo50+1
Candidate: 1:3.2.0-4~bpo50+1
Version table:
*** 1:3.2.0-4~bpo50+1 0
1 http://www.backports.org lenny-backports/main Packages
100 /var/lib/dpkg/status
1:2.4.1+dfsg-1+lenny6 0
500 http://security.debian.org stable/updates/main Packages
1:2.4.1+dfsg-1+lenny3 0
500 http://ftp.fr.debian.org stable/main Packages

By default, the 1:2.4.1 version will be installed.
If you want to install a fresher version, let’s take the one found in the backports :

root@localhost:~#apt-get -t lenny-backports install openoffice.org

It will install all the dependencies needed.

You may have already encountered some sound problems while playing several flv videos opened in different tabs. If you stop playing one of them for a while and then try to watch it again, you are unable to understand the sound that comes from the video.
Here is one solution :

In the file /etc/iceweasel/iceweaselrc, replace the line ICEWEASEL_DSP=”none” by ICEWEASEL_DSP=”aoss”

aoss is a simple wrapper script which facilitates the use of the ALSA OSS compatibility library.

To install it :

root@localhost:~#apt-get install alsa-oss

If you manage remote servers with Putty, the following tips may help you in your daily tasks :

Putty Session Manager

Putty Connection Manager

Oracle has released a new version of VirtualBox : 3.1.8.
You can download it at the following address : Download VirtualBox 3.1.8 for Debian 5.0
To see the changelog for this release : VirtualBox Changelog