Monthly Archives: November 2011

Reinstall Apache2 on Ubuntu

there is some problems when i want to reinstall apache2 through aptitude / package. when i try usual apt-get remove apache2 then apt-get install apache2 i always get this message

/etc/apache2/envvars: No such file or directory
invoke-rc.d: initscript apache2, action “start” failed.

the message then says that its probably because you have deleted dir apache2. the problem is on apache2.2-common, but simple apt-get remove or dpkg –purge wont work, mostly because thera still package dependencies that prevent the package from deletion. after googling sometime i find same post that has been solved by running this command :

[php]sudo apt-get remove –purge $(dpkg -l apache* | grep ii | awk ‘{print $2}’) && sudo apt-get install apache2[/php]

that command will aslo work for usual reinstall (reinstall without any problem before)

Virtualmin Suexec Problem

The Suexec command on your system is configured to only run scripts under /var/www, but the Virtualmin base directory is /home. CGI and PHP scripts run as domain owners will not be executed.

to solve this problem

1. install custom version of suexec
apt-get install apache2-suexec-custom
2. modify /etc/apache2/suexec/www-data
nano /etc/apache2/suexec/www-data
3. change first line /var/www to /home

it should solve the problem

Uninstall Package and It’s Configurations on Ubuntu

Ubuntu comes with package management system, apt. you can easily use apt-get to install or remove package in the other words install or remove software (program) on your ubuntu machine.

Uninstall Package on Ubuntu 11.10

Installing software command
apt-get install packagename
for example
apt-get install bind9

removing software command
apt-get remove packagename
for example
apt-get remove bind9
Continue reading Uninstall Package and It’s Configurations on Ubuntu

Internet Model – Protocol Mapping

internet end-user or we can refer to common user normally doesn’t care about how internet works. what they really want is just internet access. what they now consider maybe just speed of their internet connection and amount data transfer quota they have. but sometime knowledge about how internet works is needed. for example to explain view questions about how to check whether or not out connection work, how to solve our miss-configuration settings, etc.

Internet model can serve as guide to answer these questions. internet model comes up with protocol classification. once you know where your need is in the internet model, it will be easier for you to determine the problem and solve or at least know why the problem happened.

these are how internet models map their protocols. there are 2 internet models, OSI and TCP/IP. what we use today is actually TCP/IP model, but OSI model can somewhat help us to understand the ideal internet model.

TCP/IP model
protocol mapping on TCP/IP model
OSI model
OSI model

you can go to these wikipedia pages to learn mode about them :