Ubuntu 9.10 comes with an add/remove software called: Ubuntu Software Center.

This software can be found in: Applications => Ubuntu Software Center. Once started, you will find a list of available categories and a search box; you can navigate the categories or use the search box to search for your software.

Once you locate a program you would like to install, click on it => then click on the Forward arrow button found on the right side of the software you just clicked on => now click on the Install button => then enter your password to begin.

 
How to remove a program in Ubuntu:

To remove a program in Ubuntu => start the Ubuntu Software Center => click on Installed Software (located on the top left) => click on the software you would like to remove => click on the Forward Arrow => then click on the Remove button.

Here are some iptables commands I have found useful. This list will be updated from time to time.

View all current iptables rules:

iptables -L -v

View all INPUT rules:

iptables -L INPUT -nv

How to block an IP address using iptables:

iptables -I INPUT -s "201.128.33.200" -j DROP

To block a range of IP addresses:

iptables -I INPUT -s "201.128.33.0/24" -j DROP

How to unblock an IP address:

iptables -D INPUT -s "201.128.33.200" -j DROP

How to block all connections to a port:
To block port 25:

iptables -A INPUT -p tcp --dport 25 -j DROP
iptables -A INPUT -p udp --dport 25 -j DROP

How to un-block:
To enable port 25:

iptables -A INPUT -p tcp --dport 25 -j ACCEPT
iptables -A INPUT -p udp --dport 25 -j ACCEPT 

To save all rules so that they are not lost in case of a server reboot:

/etc/init.d/iptables save

1. First visit Google Chrome website
    
2. Scroll down to the Linux section and download the appropriate .deb file i.e. 32 bit systems or 64 bit systems.
    
3. Once the download is complete, double click on the .deb file to launch the Google Chrome installer => then click on Install Package
    
4. That is it Once installed, you can find Google Chrome in Applications => Internet => Google Chrome

Hitachi’s green datacenter:

Facebook Datacenter:

Google Datacenter:

Microsoft Datacenter:

ThePlanet Datacenter:

I personally toured ThePlanet datacenter in Dallas in 2005, very neat and beautiful setup.

Beautiful Networking Design:

Google Datacenter Tour Video:

 
Keep checking back, I will upload more.

• Google Flu Shot Finder: http://www.google.com/flushot

Currently, it is available in the United States only.

Instruction:
When you are at www.google.com/flushot => click on Change location on the top left => enter your zip code and hit Enter to display available locations near you.

Note: for Internet Explorer browser, simply click on the link then enter your zip code near “Find flu shots near:”

Legends:

H1N1 flu shots
Seasonal flu shots
Both

Reference:
Google announcement

This command will show exim processes including the path to the script being utilized to send mail. Very useful in locating a spamming script:

ps -C exim -fH eww

 

This will show the route of the email address. It is useful when you try to diagnose email delivery problems:

exim -bt user@domain.com

 

To perform a SMTP testing session as if the mail comes from a particular host for testing filtering rules inside your server:

exim -bh ipaddresshere

 

This will show what exim is currently doing:

exiwhat

 

Mail server queue:

exim -bpc   // print the total number of emails currently in server queue.
exim -bp   // print mails in queue sorting by time, size,...
exim -bp | exiqsumm   // count, volume, oldest, newest, domain, and totals

 

To list exim’s configuration setting:

exim -bP

 

To start a queue run:

exim -q -v

 

To start a queue run for just local deliveries:

 exim -ql -v

 

To remove a message from the queue:

exim -Mrm <message-id>

 

To freeze a message:

exim -Mf <message-id>

 

To force delivery of a message:

exim -M <message-id>

 

To remove all frozen messages:

exiqgrep -z -i | xargs exim -Mrm

 

To remove all messages older than 1 day (the number is in seconds):

exiqgrep -o 86400 -i | xargs exim -Mrm

 

To freeze all queued mail from a given sender:

exiqgrep -i -f user@domain.com | xargs exim -Mf

 

Message viewing:

exim -Mvh <message-id>    // view message's headers
exim -Mvb <message-id>    // view message's body
exim -Mvl <message-id>    // view message's logs

Exiqgrep

At times, we will be required to search the mail queue for a particular message to help troubleshooting mail problems for our users. Here are some useful exiqgrep commands.

 
This will search the queue for messages coming from a specific sender:

exiqgrep -f user@domain.com

 

This will search the queue for messages from a specific recipient:

exiqgrep -r user@domain.com

 

This will display messages older than the specified number of seconds.

exiqgrep -o 86400    // more than a day old

 

This will display messages newer than the specified number of seconds.

exiqgrep -y 3600    // less than an hour old

Location, configuration file:

 
Apache configuration file:

/etc/apache2/apache2.conf

 
PHP php.ini file:

/etc/php5/apache2/php.ini

 
MySQL configuration file:

/etc/mysql/my.cnf

 
Default (initial) web location:

/var/www

 
Web browser address:

http://localhost/

Restarting:

 
How to restart apache:

sudo /etc/init.d/apache2 restart

 
How to restart MySQL:

sudo /etc/init.d/mysql restart

 

 
To search for files by name:

find dir -name keyword

dir: directory you want to search for files
keyword: the name of the file you want to search for
examples:
find /home/test -name “index.txt”
find /home -name “shell*”   // find files beginging with “shell”

 
To search for files by modified date:

by the minute:

find dir -mmin time

 
by the hour:

find dir -mtime time

 
examples:
find /home -mmin -30   // find all files modified in the past 30 minutes
find /home -mmin +30   // find all files modified more than 30 minutes ago
find /home -mmin +30 -mmin -60   // find all files modified between 30 and 60 minutes ago
find /home -mtime -1   // find all files modified within the past 1-day (24 hours)
find /home -mtime -7   // find all files modified within the past 1-week (7 days)

 

 
Install a package:

rpm -ivh package_name

 
Upgrade a package:

rpm -Uvh package_name

 
Uninstall a package:

rpm -ev package_name

 
Uninstall a package without checking for its dependencies:

rpm -ev --nodeps package_name

 
Display the version of the installed package:

rpm -q package_name

 
Display the name and version of all packages installed in the server:

rpm -qa

 
Display the packages got installed recently:

rpm -qa --last

 
To rebuild a corrupted RMP database:

rpm --rebuilddb