TechieNote

How to convert MKV files to MP4 Ubuntu 12.10 / 12.04 / 11.10

Vidyadhar — Mon, 04 Feb 2013 04:10:54 +0000

Recently I have downloaded some video files from the internet which were in MKV format. I want to play the same files on my video player. But here comes the problem, my video player do not support MKV files.

As there was number of files I decided to convert the same using avconv command. “avconv” comes with libav-tools package on Ubuntu. It is the backend for many of the GUI tools cited in other answers.

Changing container without re-encoding content could not be simpler:

avconv -i input.mkv -codec copy output.mp4

It auto-detects a Matroska > MPEG4 container conversion based on input/output filenames. -codec copy tells all content should be copied as-is without re-encoding.

If format auto-detection fails, you can use the -f option before either input, output, or both. From the manual:

f fmt (input/output)

Force input or output file format. The format is normally autodetected for input files and guessed from file extension for output files, so this option is not needed in most cases.

If you want to transfer both the video and audio (both losslessly) and for it not to choke on subtitles then:

avconv -i input.mkv -c:v copy -c:a copy -sn output.mp4.

MP4 supports the most of the common audio formats used in MKVs including MP3 and AAC

Related content:

Install Configure DHCP Server Ubuntu 12.10 / 12.04 / 11.10

Vidyadhar — Mon, 28 Jan 2013 04:13:57 +0000

Dynamic Host Configuration Protocol (DHCP) is a network protocol that enables a server to automatically assign an IP address to a computer from a defined range of numbers (i.e., a scope) configured for a given network.

DHCP assigns an IP address when a system is started, for example:

A user turns on a computer with a DHCP client.
The client computer sends a broadcast request (called a DISCOVER or DHCPDISCOVER), looking for a DHCP server to answer.
The router directs the DISCOVER packet to the correct DHCP server.
The server receives the DISCOVER packet. Based on availability and usage policies set on the server, the server determines an appropriate address (if any) to give to the client. The server then temporarily reserves that address for the client and sends back to the client an OFFER (or DHCPOFFER) packet, with that address information. The server also configures the client’s DNS servers, WINS servers, NTP servers, and sometimes other services as well.
The client sends a REQUEST (or DHCPREQUEST) packet, letting the server know that it intends to use the address.
The server sends an ACK (or DHCPACK) packet, confirming that the client has a been given a lease on the address for a server-specified period of time.

When a computer uses a static IP address, it means that the computer is manually configured to use a specific IP address. One problem with static assignment, which can result from user error or inattention to detail, occurs when two computers are configured with the same IP address. This creates a conflict that results in loss of service. Using DHCP to dynamically assign IP addresses minimizes these conflicts.

For a technical review of DHCP standards, see RFCs 2131 and 2132.

Note: At Indiana University, UITS prohibits individuals and departments from setting up local DHCP servers on the IU network. Almost all wireless access points, many wired Ethernet routers, and computers running Internet Connection Sharing have built-in DHCP servers. While this makes configuration of a small network easier, it can cause problems when the DHCP servers are used in larger networks. Client computers configured to use DHCP for IP assignment do not need statically assigned IP addresses. In addition, they generally do not need to have addresses configured for DNS servers or WINS servers, as these are also set by the DHCP server.

Earlier we have seen how to install DNS server on Ubuntu 10.10 and installing local DNS server on Ubuntu. In this tutorial we will see how to setup Local DHCP server on Ubuntu 12.10.

Note: that this method will also work on Ubuntu 12.04 and 11.10

Step By Step Guide to Install and Configure DHCP Server on Ubuntu 12.10

Step 1: Make sure that the latest version is installed:

sudo apt-get install -y isc-dhcp-server

Note: Don’t be alarmed if the startup fails; that’s because you haven’t configured it yet.

Step 2.1: Enable the DCHP server on your network interface (in my case eth0):

sudo vi /etc/default/isc-dhcp-server

Step 2.2: Set INTERFACES=”" to the name of the network interface that you want to enable the DHCP server on:

INTERFACES="eth0"

Step 3.1: Edit the DHCP server configuration:

sudo vi /etc/dhcp/dhcpd.conf

Step 3.2: The contents of my configuration file, for me the comments already in the file was what I needed to make the necessary changes:

#
# Sample configuration file for ISC dhcpd for Debian
#
# Attention: If /etc/ltsp/dhcpd.conf exists, that will be used as
# configuration file instead of this file.
#
#
 
ddns-update-style none;
option domain-name "techienote.home";
option domain-name-servers server.techienote.home;
default-lease-time 600;
max-lease-time 7200;
log-facility local7;
subnet 192.168.1.0 netmask 255.255.255.0 {
  range 192.168.1.101 192.168.1.250;
  option subnet-mask 255.255.255.0;
  option broadcast-address 192.168.1.255;
  option routers 192.168.1.1;
  option domain-name-servers 192.168.1.98;
}

This needs a little bit of explaining.

Adjust your settings according to your network requirements.
The option domain name is your dns zone name. For example mine is set to techienote.home.
Range should be the range of ip addresses that you want the server to give out to clients.

Step 4: Restart the DHCP server (it should now start without problems):

sudo service isc-dhcp-server restart

Your DHCP server should be running, however it is best to check. Open up a terminal and type:

sudo netstat -uap

which will show you the following information:

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
udp        0      0 server.techienot:domain *:*                                 1002/named      
udp        0      0 localhost:domain        *:*                                 1002/named      
udp        0      0 *:bootps                *:*                                 1020/dhcpd      
udp        0      0 *:48749                 *:*                                 547/avahi-daemon: r
udp        0      0 *:29300                 *:*                                 1020/dhcpd      
udp        0      0 *:mdns                  *:*                                 547/avahi-daemon: r

Related content:

Firefox 17 New Social API | Facebook Messenger | Ubuntu 12.10 | Ubuntu 12.04

Vidyadhar — Wed, 21 Nov 2012 16:30:12 +0000

As expected Mozilla has released the new version 17 of Firefox that brings several new features and with them new controversy.

Mozilla Firefox 17 improves stability and safety thanks to fix several bugs and also adds a new feature click to play going to automatically block all third-party plugins not upgraded.

To improve the security of the browser Mozilla has decided to introduce a new feature that blocks some Flash plugin, Java, etc. obsolete due to some flaws which can endanger our security and privacy as well as the stability of the browser.

To see the complete release note, click here

This version of Firefox is faster, safer and fixes many vulnerabilities that was found in previous releases.

Right now only Facebook is supported with the new social API but Mozilla is said to be in talk with other content provided to take advantage of this feature.

To install Mozilla Firefox 17 in Ubuntu open terminal (Alt + Ctrl + t) and type the following commands

Step 1: Add Firefox repository

sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa

Step 2: Update sources.list

sudo apt-get update

Step 3: Install Firefox 17

sudo apt-get install firefox

That’s it , you have successfully installed Firefox 17. To check Firefox version type following command on terminal

firefox -v

Output would be as follows

Mozilla Firefox 17.0

To start using Messenger for Firefox go to facebook messenger for firefox page

And click on Turn On Button

When the feature is enabled, you’ll see Facebook icon and other features added to your menu bar.

Related content:

Step by Step guide to install Skype 4.1 Ubuntu 12.10 / 12.04 / 11.10

Vidyadhar — Thu, 15 Nov 2012 07:43:50 +0000

Skype is a software that allows to make free Skype-to-Skype to anyone else, call to landlines and mobiles, group chat with up to 200 people or conference call with up to 25 others.

Skype 4.1 has just been released for Linux systems which brings better compatibility for Unity and Gnome Shell.

New features and changes in this release is

Chat with your Windows Live Messenger friends on Skype
Sign in using your Microsoft account without the need to create a new Skype account
Better video quality for video chat

Currently the newest version isn’t yet available in Ubuntu Partner’s repository so you must manually download and install it.

To install Skype 4.1 in Ubuntu 12.10/12.04/11.10 open the terminal and run following commands for 32 bit platforms:

sudo apt-get install libxss1 
cd /tmp 
wget http://www.skype.com/go/getskype-linux-ubuntu-32/skype-ubuntu-precise_4.1.0.20-1_i386.deb
sudo dpkg -i skype-ubuntu*.deb

To install Skype 4.1 in Ubuntu 12.10/12.04/11.10 open the terminal and run following commands for 64 bit platforms:

sudo apt-get install libxss1 
cd /tmp 
wget wget http://www.skype.com/go/getskype-linux-ubuntu-64/skype-ubuntu-precise_4.1.0.20-1_i386.deb
sudo dpkg -i skype-ubuntu*.deb

Related content:

Install Configure local DNS Server Ubuntu 12.10 / 12.04 / 11.10

Vidyadhar — Thu, 15 Nov 2012 04:05:18 +0000

The Domain Name System (DNS) is a standard technology for managing the names of Web sites and other Internet domains. DNS technology allows you to type names into your Web browser like techienote.com and your computer to automatically find that address on the Internet. A key element of the DNS is a worldwide collection of DNS servers.

DNS server is any computer registered to join the Domain Name System. A DNS server runs special-purpose networking software, features a public IP address, and contains a database of network names and addresses for other Internet hosts.

For more info see How Internet Works

A local DNS server which performs domain name lookup is usually located on the network to which your computer is attached. If you are using an Internet Service Provider (ISP), your DNS server is at your ISP. If you are using the network at your college or your office, you probably have a local DNS server somewhere near you at the server room.

Local DNS server is very useful for small offices who use to have multiple internal websites for employees. This is the very cheap dedicated hosting solution, where you can use your LAMP server to develop websites and local DNS server for managing DNS records.

When you are on your computer, you will at some point type in the name of a computer somewhere on your local network or on the Internet. Your resolver software running on your computer looks in its local cache. If it does not find an answer, it sends that computer name to a DNS server.

Earlier we have seen how to install DNS server on Ubuntu 10.10. In this tutorial we will see how to setup Local DNS server on Ubuntu 12.10. We will be using bind9 as a local DNS Server.

Note that this method will also work on Ubuntu 12.04 and 11.10

In this whole Step By Step Guide we will be going to learn cover following topics

Installation
Configuration
	Caching Nameserver
	Primary Master
Troubleshooting
	Testing
	Logging
Some common records type

Step By Step Guide to Install and Configure Local DNS Server on Ubuntu 12.10

Step 1: We are going to use bind as our DNS server software. We will be installing bind9 on our ubuntu system. Open a command prompt and run following command to install bind9 on your system

sudo apt-get -y install bind9

Step 2: The DNS configuration files are stored in the /etc/bind directory. The primary configuration file is /etc/bind/named.conf.

The include line specifies the filename which contains the DNS options. The directory line in the /etc/bind/named.conf.options file tells DNS where to look for files. All files BIND uses will be relative to this directory.

The file named /etc/bind/db.root describes the root nameservers in the world. The servers change over time, so the /etc/bind/db.root file must be maintained now and then. This is usually done as updates to the bind9 package. The zone section defines a master server, and it is stored in a file mentioned in the file option.

It is possible to configure the same server to be a caching name server, primary master, and secondary master. A server can be the Start of Authority (SOA) for one zone, while providing secondary service for another zone. All the while providing caching services for hosts on the local LAN.

To Configure the DNS to cache requests and forward unknown requests to other DNS servers open /etc/bind/named.conf.options file :

sudo vi /etc/bind/named.conf.options

Step 2.1: Uncomment or add the forwarders section and replace the x:es with the ip-address to the primary and secondary dns of your isp:

forwarders {
        x.x.x.x;
        x.x.x.x;
};

Replace X.X.X.X with the IP Adresses of actual nameservers. I am using Google Public DNS as my forwarders, currently 8.8.8.8 and 8.8.4.4

By completing Step 1 to 2.1 your local caching nameserver is ready.

Below steps are for configuring local DNS server for small office, schools

Step 3: Make the server use its own DNS for look-ups. I always prefer to assign static ip for our critical server. For detailed explaination see How to Configure Static IP on Ubuntu

Step 3.1: Edit /etc/network/interfaces

sudo vi /etc/network/interfaces

Step 3.2: Change or add the dns-nameserver, dns-search and dns-domain directives:

# The primary network interface
auto eth0
iface eth0 inet static
        address 192.168.1.98
        netmask 255.255.255.0
        gateway 192.168.1.1
        network 192.168.1.0
        broadcast 192.168.1.255
        dns-nameservers 127.0.0.1
        dns-search techienote.home
        dns-domain techienote.home

Note 1: techienote.home is the domain name of our local network in this guide. A DNS search directive is used to eliminate the need of typing the FQDN when looking up local records.

Note 2: This setup must also be done for other Ubuntu clients that use a static IP. But then it should point to the IP of our DNS server. If you have a DHCP server you should specify your DNS IP in its settings, as well as the search domain.

Step 4: Now we will configured BIND9 as the Primary Master for the techienote.home. Simply replace techienote.home with your FQDN (Fully Qualified Domain Name).

To add a DNS zone to BIND9, turning BIND9 into a Primary Master server, the first step is to edit /etc/bind/named.conf.local:

sudo vi /etc/bind/named.conf.local

Step 4.1: Add a zone for the local domain:

zone "techienote.home" IN {
    type master;
    file "/etc/bind/zones/techienote.home.db";
};

Step 4.2: Also add a zone for reverse dns lookups for the local network:

zone "1.168.192.in-addr.arpa" {
    type master;
    file "/etc/bind/zones/rev.1.168.192.in-addr.arpa";
};

Note: Make sure that it’s literal quotes that are used, so that they aren’t converted if you copy and past them to the terminal. You get literal quotes on a Swedish keyboard by pressing “Shif+2″, on an English keybord it might be “Shif+,” ?

Step 5: Create the zones directory

sudo mkdir /etc/bind/zones

Step 6: Configure the local domain:

sudo vi /etc/bind/zones/techienote.home.db

Step 6.1: Example settings, change to match your host names and ip-addresses:

; Use semicolons to add comments.
; Host-to-IP Address DNS Pointers for techienote.home
; Note: The extra “.” at the end of the domain names are important.
 
; The following parameters set when DNS records will expire, etc.
; Importantly, the serial number must always be iterated upward to prevent
; undesirable consequences. A good format to use is YYYYMMDDII where
; the II index is in case you make more that one change in the same day.
$ORIGIN .
$TTL 86400      ; 1 day
techienote.home. IN SOA server.techienote.home. hostmaster.techienote.home. (
    2012111302 ; serial
    8H ; refresh
    4H ; retry
    4W ; expire
    1D ; minimum
)
 
; NS indicates that server is the name server on techienote.home
techienote.home. IN NS server.techienote.home.
 
$ORIGIN techienote.home.
 
; Set the address for localhost.techienote.home
localhost    IN A 127.0.0.1
 
; Set the hostnames in alphabetical order
server       IN A 192.168.1.98

Step 6.2: Create and edit the reverse lookup configuration file

sudo vi /etc/bind/zones/rev.1.168.192.in-addr.arpa

Example settings, reversed of the above:

; IP Address-to-Host DNS Pointers for the 192.168.1 subnet
@ IN SOA server.techienote.home. hostmaster.techienote.home. (
    2012111302 ; serial
    8H ; refresh
    4H ; retry
    4W ; expire
    1D ; minimum
)
; define the authoritative name server
           IN NS server.techienote.home.
; our hosts, in numeric order
98        IN PTR server.techienote.home.

Note : You must increment the Serial Number every time you make changes to the zone file. If you make multiple changes before restarting BIND9, simply increment the Serial once. Many admins like to use the last date edited as the serial of a zone, such as 2012010100 which is yyyymmddss (where ss is the Serial Number)

Step 7: Restart services to use the new settings:

sudo service bind9 restart

Step 8: Restart the network interface that you changed in step 3.2:

sudo nohup sh -c "ifdown eth0 && ifup eth0"

Note : that networking restart has been deprecated, see this post for more information.

Your DNS server should be running, however it is best to check. Open up a terminal and type:

sudo netstat -uap

which will show you the following information:

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
udp        0      0 server.techienot:domain *:*                                 1002/named      
udp        0      0 localhost:domain        *:*                                 1002/named      
udp        0      0 *:bootps                *:*                                 1020/dhcpd      
udp        0      0 *:48749                 *:*                                 547/avahi-daemon: r
udp        0      0 *:29300                 *:*                                 1020/dhcpd      
udp        0      0 *:mdns                  *:*                                 547/avahi-daemon: r

Step 9: Test that the dns look-ups works with the local server:

host techienote.com

The response should be:

techienote.com has address 174.122.2.251
techienote.com mail is handled by 0 techienote.com.

Step 10: Test that all of your computers are listed with the following command:

host -l techienote.home

The output should list all of your entered hosts:

techienote.home name server server.techienote.home.
localhost.techienote.home has address 127.0.0.1
server.techienote.home has address 192.168.1.98

Step 11: Test that the reverse lookup works:

host 192.168.1.98

Response:

98.1.168.192.in-addr.arpa domain name pointer server.techienote.home.

Another way to test your zone files is by using the named-checkzone utility installed with the bind9 package. This utility allows you to make sure the configuration is correct before restarting BIND9 and making the changes live.

Step 12: To test our techienote Forward zone file enter the following from a command prompt:

named-checkzone techienote.home /etc/bind/zones/techienote.home.db

If everything is configured correctly you should see output similar to:

zone techienote.home/IN: loaded serial 6
OK

Step 13: Similarly, to test the Reverse zone file enter the following:

named-checkzone 1.168.192.in-addr.arpa /etc/bind/zones/rev.1.168.192.in-addr.arpa

The output should be similar to:

zone 1.168.192.in-addr.arpa/IN: loaded serial 3
OK

Note 1 : The Serial Number of your zone file will probably be different.

Note 2 : The default directory for non-authoritative zone files is /var/cache/bind/ This directory is also configured in AppArmor to allow the named daemon to write to it

Note 3 : By default you BIND9 logs will get recored in /var/log/syslog

Step 14: BIND9 has a wide variety of logging configuration options available. There are two main options. The channel option configures where logs go, and the category option determines what information to log.

If no logging option is configured the default option is:

logging {
     category default { default_syslog; default_debug; };
     category unmatched { null; };
};

Step 15: If you want to send debug messages related to DNS queries to a separate file you need to edit /etc/bind/named.conf.local and add the following:

logging {
channel query.log {      
    file "/var/log/query.log";
    severity debug 3; 
}; 
};

Step 16: Next, configure a category to send all DNS queries to the query file:

logging {
channel query.log {      
    file "/var/log/query.log"; 
    severity debug 3; 
}; 
category queries { query.log; }; 
};

Note: the debug option can be set from 1 to 3. If a level isn’t specified level 1 is the default.

Step 17: Since the named daemon runs as the bind user the /var/log/query.log file must be created and the ownership changed:

sudo touch /var/log/query.log
sudo chown bind /var/log/query.log

Step 18: Before named daemon can write to the new log file the AppArmor profile must be updated. First, edit /etc/apparmor.d/usr.sbin.named and add:

/var/log/query.log w,

Step 19: Next, reload the profile:

cat /etc/apparmor.d/usr.sbin.named | sudo apparmor_parser -r

Step 20: Now restart BIND9 for the changes to take effect:

sudo service bind9 restart

You should see the file /var/log/query.log fill with query information. This is a simple example of the BIND9 logging options.

Common Record Types

Following are the most common DNS record types you should know.

A record: This record maps an IP Address to a hostname.

www      IN    A      192.168.1.98

CNAME record: Used to create an alias to an existing A record. You cannot create a CNAME record pointing to another CNAME record.

web     IN    CNAME  www

MX record: Used to define where email should be sent to. Must point to an A record, not a CNAME.

IN    MX  1   mail.techienote.home.
mail    IN    A       192.168.1.98

NS record: Used to define which servers serve copies of a zone. It must point to an A record, not a CNAME. This is where Primary and Secondary servers are defined.

You should have a firewall between this server and the internet and make sure that the dns port (53) is not forwarded to your Ubuntu server. Otherwise your dns server will be open for anyone in the world to use. With this setup it is only intended to be used within your local network.

Related content:

Tweak Ubuntu OS with Ubuntu Tweak

Vidyadhar — Thu, 08 Nov 2012 03:33:17 +0000

Ubuntu Tweak is an application designed to config Ubuntu easier for everyone. It provides many useful desktop and system options that the default desktop environment does’t provide.

At present, it’s only designed for the Ubuntu GNOME Desktop, and always follows the newest Ubuntu distribution.

With Ubuntu Tweak you can do following things.

View of Basic System Information(Distribution, Kernel, CPU, Memory, etc.)
GNOME Session Control
Auto Start Program Control
Quick install popular applications
A lot of third-party sources to keep applications up-to-date
Clean unneeded packages or cache to free disk space
Show/Hide and Change Splash screen
Show/Hide desktop icons or Mounted Volumes
Show/Hide/Rename Computer, Home, Trash or Network icon
Tweak Metacity Window Manager’s style and behaviour
Compiz Fusion settings, Screen Edge Settings, Window Effect Settings, Menu Effect Settings
Set the Shortcuts to archive quicker access your favourite applications
GNOME Panel Settings
Nautilus Settings
Advanced Power Management Settings
System Security Settings

In this new version the “Love Wallpaper HD” is officially introduced. You can browser the random wallpapers that fit your screen size in it. By clicking “I’m Feeling Lucky” you can always get new pictures, by double-clicking the picture, Ubuntu Tweak will download and set the wallpaper for you automatically.

The picture will be saved at ~/.config/ubuntu-tweak/lovewallpaper.jpg, if you like it, you can move it out.

By following below methods you can install Ubuntu Tweak on Ubuntu 12.10, 12.04 and 11.10

Step 1 Open a command prompt

Step 2 Run following commands

sudo add-apt-repository ppa:tualatrix/ppa
sudo apt-get update
sudo apt-get install ubuntu-tweak

Ubuntu Tweak debs can also be downloaded via Launchpad.

Related content:

Step By Step Guide to Install Oracle Database Express Edition 11GR2 On Ubuntu 12.10 / 12.04 / 11.10

Vidyadhar — Mon, 05 Nov 2012 04:22:00 +0000

Oracle Database Express Edition 11gR2 is free for download and is available for variety of platforms including various distros of Linux and Microsoft Windows without needing a license. in this this guide will show you how to install Oracle Database Express Edition 11gR2 on Ubuntu 12.10. Note that this method will also work on Ubuntu 12.04 and 11.10

If you want to install Enterprise Edition of Oracle Database on Ubuntu then follow below post
How to install Oracle Database 11g R2 on Ubuntu 12.04

So lets start now.

Step 1. Managing Swap partition. Oracle Database Express Edition 11gR2 may require up to a 2GB (2095100 KB) swap partition, Enter the following command in terminal to verify your swap space:

cat /proc/meminfo | grep -i swap

If you don’t have enough swap space, you can increase available swap space by the following guide to create and enable swap partiton, in this case I’ll create 1 GB swap file and loaded at startup, located in the /home directory

sudo -i

Create swap file on /home directory with following commands:

dd if=/dev/zero of=/home/swapfile bs=1024 count=1048576
mkswap /home/swapfile
swapon /home/swapfile
swapon -a

Create a backup of the original “fstab” file and add the new swap file:

cp /etc/fstab /etc/fstab.backup_`date +%N`
echo '/home/swapfile swap swap defaults 0 0' >> /etc/fstab

Logout from root and verify the new swap space:

exit
swapon -s

Step 2. Install additional software thats require Oracle 11g Express Edition

sudo apt-get install alien libaio1

Step 3. Download Oracle Database Express Edition 11gR2 via Oracle Official website, it require registration before downloading.

Step 4. unzip the downloaded file, then convert the Oracle Database Express Edition 11gR2 package installer to debian package

unzip oracle-xe-11.2.0.1.0.x86_64.rpm.zip
cd Disk1/
sudo alien --to-deb --scripts oracle-xe-11.2.0-1.0.x86_64.rpm

Step 5. Configure Awk and Chkconfig, The following needs to be set for compatibility:

sudo ln -s /usr/bin/awk /bin/awk
sudo mkdir /var/lock/subsys

Ubuntu uses different tools to manage services and system startup scripts. The “chkconfig” tool required by the Oracle installer is not available in Ubuntu. The following will create a file to simulate the “chkconfig” tool.

sudo -i

Copy and paste the following Script directly into the terminal to create a file chkconfig:

cat > /sbin/chkconfig <<-EOF
#!/bin/bash
# Oracle 11gR2 XE installer chkconfig, Only run once.
echo "Simulating /sbin/chkconfig..."
if [[ ! `tail -n1 /etc/init.d/oracle-xe | grep INIT` ]]; then
cat >> /etc/init.d/oracle-xe <<-EOM
#
### BEGIN INIT INFO
# Provides: OracleXE
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Oracle 11g Express Edition
### END INIT INFO
EOM
fi
update-rc.d oracle-xe defaults 80 01
EOF

Logout form root:

exit

Set the file /sbin/chkconfig executable :

sudo chmod 755 /sbin/chkconfig

Step 6. Install Oracle Database Express Edition 11gR2 with the following commands:

cd ~/Downloads/Disk1
sudo dpkg -i oracle-xe-11.2.0-1.0.x86_64.deb

Run the following configuration script to create (clone) the database. Accept the default answers, including “y” to startup the database automatically, or modify as required.

sudo /etc/init.d/oracle-xe configure

To verify success, the procedure should end showing:

Starting Oracle Net Listener...
Done Configuring database...
Done Starting Oracle Database 11g Express Edition instance...
Done Installation completed successfully.

Step 7. Set a password for the Oracle account:

sudo passwd oracle

Step 8. Post-Installation, In order to use sqlplus and other tools, the Oracle account requires specific environment variables. The following will set these variables automatically at every Oracle login:

su - oracle

Copy the default account skeleton files and add the Oracle env script to .profile:

cp /etc/skel/.bash_logout ./ 
cp /etc/skel/.bashrc ./ 
cp /etc/skel/.profile ./ 
echo "" >>./.profile
echo '. /u01/app/oracle/product/11.2.0/xe/bin/oracle_env.sh' >>./.profile

Step 9. Configure remote login. By default, the Oracle Database XE graphical user interface is only available at the local server, but not remotely. The following will enable remote logins:

su - oracle
sqlplus / as sysdba
SQL> EXEC DBMS_XDB.SETLISTENERLOCALACCESS(FALSE);
exit

Related content:

How to download and install Google Chrome browser on Ubuntu 12.10

Vidyadhar — Sat, 03 Nov 2012 09:46:25 +0000

Mozila Firefox comes as default browser in Ubtunu 12.10. As a secondary web browser for testing purpose I used to install Google Chrome. Google Chrome is a freeware web browser developed by Google that uses the WebKit layout engine. Google Chrome had 34% worldwide usage share of web browsers making it the most widely used web browser. W3Counter indicated that Chrome became the leading browser globally in August 2012 with 28% marketshare.

Here is the simple tutorial to download and install Google Chrome on Ubuntu 12.10, 12.04 and 11.10

Step 1 Open a terminal by pressing Ctrl + Alt + T on your keyboard

Step 2 Type in the following commands then hit Enter after each.

wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
 
sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
 
sudo apt-get update
 
sudo apt-get -y install google-chrome-stable

That’s it. Enjoy your browsing with Google Chrome

Related content:

Install VLC Free Media Player on Ubuntu 12.10, 12.04, 11.10

Vidyadhar — Fri, 02 Nov 2012 04:22:53 +0000

VLC is a free and open source cross-platform multimedia player and framework that plays most multimedia files as well as DVD, Audio CD, VCD, and various streaming protocols. VLC is a simple, fast and powerful dvd playing, media playing software. VLC can play everything i.e. Files, Discs, Webcams, Devices and Streams. VLC can plays most codecs with no codec pack needed, MPEG-2, DivX, H.264, MKV, WebM, WMV, MP3.

The main advantage is VLC is cross-platform multi media player. VLC can runs on all platforms: Windows, Linux, Mac OS X, Unix. We can use VLC for media conversion and streaming.

This is the simple howto in which we will see how to install VLC media player on Ubuntu 12.10. Note that this procedure you can also use for Ubuntu 12.04 and 11.10

To install VLC in Ubuntu open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

sudo add-apt-repository ppa:videolan/stable-daily
sudo apt-get update
sudo apt-get install vlc

That’s it. Enjoy your free multi media player on ubuntu.

Related content:

How to Download and Install IBM DB2 Database on Ubuntu

Vidyadhar — Tue, 30 Oct 2012 04:04:50 +0000

IBM DB2 database software offers industry leading performance, scale, and reliability on your choice of platform from Linux, Unix and Windows to z/OS.

IBM DB2 database comes in following editions

Enterprise Server Edition
Advanced Enterprise Server Edition
Workgroup Server Edition
Express-C
Express Edition

For this tutorial we are going to install IBM DB2 Express-C 10.1 edition on Ubuntu 12.04 and Ubuntu 12.10 32 bit OS.

IBM DB2 Express-C is the free edition of the IBM DB2 database server. You can download and install DB2 Express-C on your own machine freely. You can also provision your own DB2 Express-C server in the cloud. Finally, there is a set of free tools for administration and development.

The most important thing about IBM DB2 Express-C is it provides all the core capabilities of DB2 at no charge.

To download IBM DB2 go to http://www-01.ibm.com/software/data/db2/express/download.html

Step 1: Install the base system

Here I am assuming that you are installing IBM DB2 Express-C on fresh Ubuntu 12.04 installation.

Step 1.1 You need to run following commands to upgrade your system as latest stable and other useful packages:

sudo apt-get update
sudo apt-get -y install aptitude tasksel 
sudo aptitude update
sudo aptitude -y full-upgrade
sudo tasksel install openssh-server
sudo tasksel install server
sudo tasksel install mail-server
sudo aptitude -y install colordiff mlocate ntp pwgen rsync vim

Also note that you must have X11 server install on the ubuntu box. If you are connecting to the ubuntu box using putty you have to enable X11 forwarding. Refer this post to simplify the process.

Run following commands to install X11 server

sudo aptitude -y install lxde-core xorg

Step 1.2 Check your /etc/hostname and update as below:

localhost.localdomain

Step 1.3 Check your /etc/hosts and update as below:

127.0.0.1       localhost.localdomain   localhost

Step 1.4 Check your /etc/resolv.conf and update as below:

search localdomain

Step 1.5 Set the timezone properly by running following command

sudo dpkg-reconfigure tzdata

At this point your Ubuntu 12.04 should basically configure for installing DB2 Express-C 10.1. Reboot your machine.

Step 2: Check your hardware setup

Step 2.1 First of all, you need to have AT LEAST 1GB of physical memory (I use 2GB here). Check it with:

grep MemTotal /proc/meminfo

Step 2.2 On the other hand, it is suggest to have swap with 1.5 time of your physical memory, e.g. around 2GB. Check it with:

grep SwapTotal /proc/meminfo

Step 2.3 Shared memory is very important, too. Or else you may face the ORA-00845 error message. First check it with:

df -kh /dev/shm/

Step 2.3.1 If you have less than 512MB (I will suggest for 1GB), edit your /etc/fstab and add/modify the following line:

tmpfs           /dev/shm        tmpfs   defaults,size=1024M    0       0

Step 2.3.2 Then remount it and check the size once again:

mount -o remount /dev/shm
df -kh /dev/shm/

Step 3: Install dependence packages
As I assume you have Ubuntu 12.04 installed correctly with X11, we just need to install some more packages for IBM DB2 Express-C.
Run following command to install dependencies

sudo aptitude -y install alien binutils build-essential cpp-4.4 debhelper g++-4.4 gawk gcc-4.4 gcc-4.4-base gettext html2text ia32-libs intltool-debian ksh lesstif2 lib32bz2-dev lib32z1-dev libaio-dev libaio1 libbeecrypt7 libc6 libc6-dev libc6-dev-i386 libdb4.8 libelf-dev libelf1 libltdl-dev libltdl7 libmotif4 libodbcinstq4-1 libodbcinstq4-1:i386 libqt4-core libqt4-gui libsqlite3-0 libstdc++5 libstdc++6 libstdc++6-4.4-dev lsb lsb-core lsb-cxx lsb-desktop lsb-graphics lsb-qt4 make odbcinst openjdk-6-jdk pax po-debconf rpm rpm-common sysstat tzdata-java unixodbc unixodbc-dev unzip

Step 4: Configure kernel parameters
Step 4.1 We also need to modify the kernel parameter, to do so run following commands as root

echo "#">> /etc/sysctl.conf
echo "# Oracle 11gR2 entries">> /etc/sysctl.conf
echo "fs.aio-max-nr=1048576" >> /etc/sysctl.conf
echo "fs.file-max=6815744" >> /etc/sysctl.conf
echo "kernel.shmall=2097152" >> /etc/sysctl.conf
echo "kernel.shmmni=4096" >> /etc/sysctl.conf
echo "kernel.sem=250 32000 100 128" >> /etc/sysctl.conf
echo "net.ipv4.ip_local_port_range=9000 65500" >> /etc/sysctl.conf
echo "net.core.rmem_default=262144" >> /etc/sysctl.conf
echo "net.core.rmem_max=4194304" >> /etc/sysctl.conf
echo "net.core.wmem_default=262144" >> /etc/sysctl.conf
echo "net.core.wmem_max=1048586" >> /etc/sysctl.conf
echo "kernel.shmmax=1073741824" >> /etc/sysctl.conf

Note: kernel.shmmax = max possible value, e.g. size of physical memory in bytes. In my case machine is having 2GB so we are specifying 1GB. Adjust the parameter as per your configuration

Step 4.2 Load new kernel parameters, by running following,

sudo sysctl -p

Step 5: Extracting binaries
Step 5.1 First of all, login with root, with X enabled.
Step 5.2 Copy the file db2_v101_linuxx64_expc.tar.gz to temporary directory, then extract it:

cp db2_v101_linuxia32_expc.tar.gz /usr/local/src
cd /usr/local/src
tar zxvf db2_v101_linuxia32_expc.tar.gz

Reboot your machine.

Step 6: Starting Installation
Step 6.1 First of all login with root and start the X11 with startx, then start the installer with:

cd /usr/local/src/expc/
./db2setup

Step 6.2 Next we go though the installation:

Step 6.2 Choose “Install a Product” then press on “Install New”:

Step 6.3 The “Welcome to the DB2 Setup wizard” screen will now show up:

Step 6.3 Accept the “Software License Agreement” to go ahead;

Step 6.4 During “Select the installation type” I would like to use “Custom – 760 MB” installation so able to get full control:

Step 6.5 In “Select installation, response file creation, or both” just use default setup:

Step 6.6 In “Select the features to install” I just click “Select all” so everything should install correctly:

Step 6.7 In “Select the languages to install” again I choose English:

Step 6.8 In “Specify the location of the DB2 Information Center” I will get information by “On the IBM Web site”:

Step 6.9 In “Set user information for the DB2 Administration Server”, create the user for DAS

Step 6.10 In “Set up a DB2 instance”, choose “Create a DB2 instance”:

Step 6.11 In “Set user information for the DB2 instance owner”, we will create an user account for our new instance

Step 6.12 In “Set user information for the fenced user”, create user account as similar as above:

Step 6.13 In “Configure instance communication and startup”, just keep as default:

Step 6.14 In “Set up notifications” I selected “Do not set up your DB2 server to send notification at this time” as I have not setup the mail server:

Step 6.15 In “Configure the DB2 Text Search service”, again just keep as default:

Step 6.16 Ok is time for final confirmation, we also get it done:

I have copied the configuration details for ref

Product to install:                        DB2 Express-C 
Installation type:                         Custom 
 
Previously Installed Components:        
 
Selected Components:                    
    Base client support                    
    Java support                           
    SQL procedures                         
    Base server support                    
    Communication support - TCP/IP         
    DB2 data source support                
    Spatial Extender server support        
    DB2 LDAP support                       
    DB2 Instance Setup wizard              
    Base application development tools     
    DB2 Update Service                     
    First Steps                            
    Sample database source                 
    DB2 Text Search                        
 
Languages:                              
    English                                
        All Products                       
 
Target directory:                          /app/ibm/db2/V10.1
 
Space required:                            751 MB
 
New instances:                          
    Instance name:                         db2inst1
        Start instance on reboot:          Yes 
        TCP/IP configuration:              
            Service name:                  db2c_db2inst1
            Port number:                   50000
        Instance user information:         
            User name:                     db2inst1
            Group name:                    db2iadm1
            Home directory:                /home/db2inst1
        Fenced user information:           
            User name:                     db2fenc1
            Group name:                    db2fadm1
            Home directory:                /home/db2fenc1
        DB2 Text Search:                   
            HTTP service name:             db2j_db2inst1
            HTTP service port number:      55000
 
DB2 Administration server:              
    Instance user information:             
        User name:                         dasusr1
        Group name:                        dasadm1
        Home directory:                    /home/dasusr1
 
Response file name:                        /root/db2expc.rsp

Step 6.17 In case of successful setup you will see following screen

Step 7: Post-installation procedure
Before we go to next step, let’s check the following tasks:

Step 7.1 The default shell for dasuser1, db2instl and db2fencl are sh. Edit /etc/passwd and update them as bash.
Step 7.2 Kill your X, logout, re-login with db2inst1, then run startx (or directly for db2fs/db2cc if you are using Putty + Xming)
Step 7.3 Open a terminal and start db2fs:

db2fs

Step 7.3 db2fs will ask for your default web browser. Answer /usr/bin/firefox here:

Step 7.4 This will open the “First Steps for DB2 Database for Linux, UNIX, and Windows” in Firefox. Now click on “Create SAMPLE database”:

Step 7.5 In “First Steps – Create SAMPLE Database”, just keep as default:

Step 7.6 In case of successful creation you will see following screen

Related content: