Saidar is a curses-based application to display system statistics.
The statistics include CPU, processes, load, memory, swap, network I/O and disks I/O.

Saidar uses the library libstatgrab. libstatgrab is a cross-platform library that provides access to statistics on the system that runs it.  The current list of statistics includes CPU usage, memory usage, disk usage, process counts, network traffic, disk I / O, and more.

Step1. Install Saidar on Debian Squeeze:

apt-get install saidar

Step2. Using saidar:

After having installed it, you can type in the command saidar:

root@css:~# saidar

For more info you can view the man page using the command : “man saidar”

Piwik is a  source, open (GPL) web real-time analysis software. It provides detailed reports about visitors on your website like: search engines,  keywords used, the language they speak, your popular pages .
Piwik is an alternative to Google Analytics, and is already used by more than 150,000 websites.
Piwik is an PHP MySQL software program that you can download and install on your own web server. At the end of installation process you will be given five minutes JavaScript code.
Simply copy and paste this tag on websites that wish to track  and access your reports real-time analysis.

You can Download the latest Piwik release and install it on your server. You will need at least PHP5.1 and MySQL to make piwik to work.

Install Piwik on Debian Squeeze:

Step1.  First we need to download the latest release of Piwik from http://piwik.org/latest.zip :

wget http://piwik.org/latest.zip

Step2. Then unzip the downloaded file. This will  create a “piwik” folder containing files and directories.

unzip latest.zip

On Debian systems … Apache comes with mod_status compiled by default.
mod_status provides information on the Apache server activity and performance.
This tutorial will show you how to enable this feature, so that only requested issued from localhost are accepted and served.

Setting mod_status up:

By default, server status report is commented so you can not access it. To enable it, you need to uncomment from /etc/apache2/apache2.conf:

<Location /server-status>
    SetHandler server-status
    Order deny,allow
    Deny from all
    Allow from .your_domain.com
</Location>

BitMeter OS is a free, open-source, bandwidth monitor that works on Windows, Linux and Mac OSX.
BitMeter OS keeps track of how much you use your internet/network connection, and allows you to view this information either via a web browser,
or by using the command line tools.

The Web Interface displays various graphs and charts that show how your internet/network connection has been used over time.

The Monitor pane displays a graph that updates once each second, showing you what’s happening with your connection right now:

Have you ever having to control more than a single file with your tail -f ?

I will and I just recently found out that you can run the tail command specifying the -f flag several times so you can give the command:

tail -f /var/log/messages -f /var/log/syslog

You’ll get an output like this:

==> messages <== Nov 22 00:43:07 laptop kernel: [ 61.487969] ADDRCONF(NETDEV_UP): eth0: link is not ready

==> syslog <== Nov 22 00:43:31 laptop pulseaudio[1773]: ratelimit.c: 1 events suppressed

==> messages <== Nov 22 00:43:31 laptop pulseaudio[1773]: ratelimit.c: 1 events suppressed

==> syslog <==

Nov 22 00:45:44 laptop ntpd[1118]: kernel time sync status change 6001