Some useful usages of dpkg

# dpkg -i [package.deb] install update a .deb
# dpkg -r [package] remove a .deb
# dpkg -l list all .deb installed on system
# dpkg -s [package] info on a package
# dpkg -L [package] show list of files provided by a installed package
# dpkg --contents [package.deb] show list of files provided by a not installed package
# dpkg -S /bin/ping check the package that owns the file

debsums tool for maintenance and recovery in Debian GNU/Linux

Very usefull to discover rapidly where you have put hands on in your system.
examples of use http://arthurdejong.org/recovery.html to recovery a system broken.

no network connection with java apps on debian lenny

If you are experiencing problem like no network connection on debian (the current testing distribution - squeeze for me) from java applications. Ex:

"java.net.SocketException: Network is unreachable"

but, connection is working for others kinds of apps probably you can solve it: editing file
/etc/sysctl.d/bindv6only.conf
and set net.ipv6.bindv6only 0
and after /etc/init.d/invoke-rc.d procps restart (to reboot procfs).

Seems that the jdk is not managing correctly ipv6 connections...
The bug is reported for sun-jdk and open-jdk packages.

source.

Debian lenny unlock button blocked for some administrative tools

I solved the problem:

unlock (authentication) button blocked for some administrative tools

installing the packege policykit-gnome.

See a discussion here

bye.

Nvidia 8600M GS on Debian Lenny for acer 5920G-813G25Mi

from tty (ctrl+alt + [F1-F6])

/etc/init.d/gdm stop
apt install nvidia-glx
edit /etc/X11/xorg.conf
add to section device Driver "nvidia"
/etc/init.d/gdm restart

done!