Omnipresent IT Solutions Pvt Ltd

Monday, August 24, 2009

Virtualbox not working after re-installing kernel

VirtualBox

VirtualBox is a powerful x86 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL).

http://www.virtualbox.org/

Virtualbox not working after re-installing kernel

In Fedora 11

Go to /etc/init.d/

And run ./vboxdrv setup

It will Recompile VirtualBox kernel module



For other OS users, post your problem here.

Wednesday, August 5, 2009

How to restore GRUB menu after Windows installation



How to restore GRUB menu after Windows installation

  1. Boot from the CD/DVD and at the boot prompt type: linux rescue.
  2. Select your language and keyboard layout.
  3. Choose whether or not to start networking interfaces.
  4. Mount your partitions read/write.
  5. Type chroot /mnt/sysimage to enter your Linux environment.
  6. Type grub-install /dev/sda or grub-install /dev/hda
  7. Reboot.

To add Windows entry into GRUB menu

Take a backup first
cp /boot/grub/menu.lst /boot/grub/menu.lst_backup

Edit the file and add following line at the end of file
/boot/grub/menu.lst

#windows
title Microsoft Windows
root (hd0,0)
savedefault
makeactive
chainloader +1


A sample menu.lst file

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,1)
# kernel /vmlinuz-version ro root=/dev/mapper/vg_acerfedora-lv_root
# initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=15
splashimage=(hd0,1)/grub/splash.xpm.gz
#hiddenmenu
title Fedora (2.6.29.6-217.2.3.fc11.i686.PAE)
root (hd0,1)
kernel /vmlinuz-2.6.29.6-217.2.3.fc11.i686.PAE ro root=/dev/mapper/vg_acerfedora-lv_root quiet
initrd /initrd-2.6.29.6-217.2.3.fc11.i686.PAE.img
title WindowsVista
rootnoverify (hd0,0)
chainloader +1

Note:You can change timeout,default values by editing this file.

Tuesday, August 4, 2009

Sunday, August 2, 2009

Configuring paths for Java and Oracle on fedora







Configuring paths for Java1.6.0_0 and Oracle 11g on fedora 11



Prerequisites:
1. Oracle 11g installed(You can refer my earlier posts)
2. Jdk installed(You can refer my earlier posts)

Adding Paths

Add these paths to the .bash_profile file in your oracle home directory
-----------------------------------------------------------------------
TMP=/tmp; export TMP

TMPDIR=$TMP; export TMPDIR

ORACLE_HOSTNAME=acerfedora; export ORACLE_HOSTNAME

ORACLE_BASE=/u01/app/oracle; export ORACLE_BASE

ORACLE_HOME=$ORACLE_BASE/product/11.1.0/db_1; export ORACLE_HOME

ORACLE_SID=orcl; export ORACLE_SID

ORACLE_TERM=xterm; export ORACLE_TERM

JAVA_HOME=/usr/lib/jvm/java-1.6.0 export JAVA_HOME

PATH=/usr/sbin:$PATH; export PATH

PATH=$ORACLE_HOME/bin:$PATH; export PATH

PATH=$JAVA_HOME/bin:$PATH; export PATH

LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib:$ORACLE_HOME/jdbc/lib; export LD_LIBRARY_PATH

CLASSPATH=$ORACLE_HOME/JRE:.:$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib:$ORACLE_HOME/jlib/orai18n.jar:$ORACLE_HOME/jdbc/lib/ojdbc6.jar:/usr/share/java:/usr/share/java/servlet-api-2.5.jar:/usr/share/java/mysql-connector-java-5.1.6.jar:/usr/share/java/commons-dbcp-1.2.1.jar;
export CLASSPATH
------------------------------------------------------------------------------------------

Checking Java

[oracle@acerfedora ~]$ java -version
java version "1.6.0_0"
OpenJDK Runtime Environment (IcedTea6 1.5) (fedora-25.b16.fc11-i386)
OpenJDK Server VM (build 14.0-b15, mixed mode)

Starting Oracle

[oracle@acerfedora ~]$ lnsrctl start
bash: lnsrctl: command not found
[oracle@acerfedora ~]$ clear

[oracle@acerfedora ~]$ lsnrctl start

LSNRCTL for Linux: Version 11.1.0.6.0 - Production on 03-AUG-2009 04:48:09

Copyright (c) 1991, 2007, Oracle. All rights reserved.

Starting /u01/app/oracle/product/11.1.0/db_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 11.1.0.6.0 - Production
System parameter file is /u01/app/oracle/product/11.1.0/db_1/network/admin/listener.ora
Log messages written to /u01/app/oracle/diag/tnslsnr/acerfedora/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=acerfedora)(PORT=1521)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.1.0.6.0 - Production
Start Date 03-AUG-2009 04:48:09
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.1.0/db_1/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/acerfedora/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=acerfedora)(PORT=1521)))
The listener supports no services
The command completed successfully

Note:To stop use [oracle@acerfedora ~]$ lsnrctl stop

[oracle@acerfedora ~]$ dbstart
ORACLE_HOME_LISTNER is not SET, unable to auto-start Oracle Net Listener
Usage: /u01/app/oracle/product/11.1.0/db_1/bin/dbstart ORACLE_HOME
Processing Database instance "orcl": log file /u01/app/oracle/product/11.1.0/db_1/startup.log

Note: To stop use [oracle@acerfedora ~]$ dbshut


Example program:atm.java

To verify the connection compile and run this example
class atm {
public static void main (String args []) throws SQLException
{
DriverManager.registerDriver (new oracle.jdbc.driver.OracleDriver());

Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl", "scott", "oracle");
// @machineName:port:SID, userid, password

Statement stmt = conn.createStatement();
ResultSet rset = stmt.executeQuery("select BANNER from SYS.V_$VERSION");
while (rset.next())
System.out.println (rset.getString(1)); // Print col 1
stmt.close();
}
}

Compile: javac atm.java
Run: java atm
Output:
[oracle@acerfedora jsp]$ java atm
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
PL/SQL Release 11.1.0.6.0 - Production
CORE 11.1.0.6.0 Production
TNS for Linux: Version 11.1.0.6.0 - Production
NLSRTL Version 11.1.0.6.0 - Production

You can use Oracle Enterprise Manager 11g for further work

[oracle@acerfedora jsp]$ emctl start dbconsole
Oracle Enterprise Manager 11g Database Control Release 11.1.0.6.0
Copyright (c) 1996, 2007 Oracle Corporation. All rights reserved.
https://acerfedora:1158/em/console/aboutApplication
Starting Oracle Enterprise Manager 11g Database Control .......... started.

Logs are generated in directory /u01/app/oracle/product/11.1.0/db_1/acerfedora_orcl/sysman/log

Note: To stop [oracle@acerfedora jsp]$ emctl stop dbconsole


http://www.oracle.com/technology/software/products/database/index.html

Tomcat Server Configurations

Add these 2 files to /usr/share/tomcat5/common/lib

ojdbc6_g.2.jar and tools.jar

You wil get ojdbc6_g.2.jar from /u01/app/oracle/product/11.1.0/db_1/jdbc/lib

(or ur $ORACLE_HOME/jdbc/lib)

You wil get tools.jar from /usr/lib/jvm/java-1.6.0/lib

(or $JAVA_HOME/lib)

bash: ls: command not found

Don't Worry

This occurs when you edit your .bashrc file in your home folder
Suppose you edited your /root/.bashrc file as root folder.. Then you will not be able to do any commands.. No other users can change roots file also..

Solution
--------------
Take the terminal
[sarith@acerfedora ~]$ export PATH=/bin or to the path where your ls executable resides
Now you will be able to work with ls command. Come to home folder of the user

[sarith@acerfedora ~]$ export PATH=/usr/bin

Now you will be able to use gedit or vi or any other editor.Edit .bashrc file
Delete the path you added or Add path to all directories like
/usr/lib/qt-3.3/bin:/usr/kerberos/bin:/usr/lib/ccache:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/u01/app/oracle/product/11.1.0/db_1/bin:/home/sarith/bin

Exit the shell.. It started working again.. If any other problems mail me
sarithdivakar@yahoo.co.in

Bash

NAME
bash - GNU Bourne-Again SHell



DESCRIPTION
Bash is an sh-compatible command language interpreter that executes
commands read from the standard input or from a file. Bash also incor-
porates useful features from the Korn and C shells (ksh and csh).

When Bash starts, it executes the commands in a variety of different scripts.

When Bash is invoked as an interactive login shell, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable.

When a login shell exits, Bash reads and executes commands from the file ~/.bash_logout, if it exists.

When an interactive shell that is not a login shell is started, Bash reads and executes commands from ~/.bashrc, if that file exists. This may be inhibited by using the --norc option. The --rcfile file option will force Bash to read and execute commands from file instead of ~/.bashrc.

Wednesday, July 29, 2009

Customizing the splash image in GRUB

Got bored with corporate logo of your Linux distribution?

Change it..

1.The image should be of size 640x480 pixels

2.Should only have 14 colours

3.In gzipped xpm format

You can use GIMP for these modifications and save it as xpm file. Then gzip and make it splash.xpm.gz

Back up your /boot/grub/splash.xpm.gz and overwrite with your file

Note: You need root privileges

Done! Reboot and watch...

Here is my lap's bootupscreen..

Monochrome images in grey scale, red, blue or green work better than other colours. I used grayscale...

Sunday, July 26, 2009

Complete Guide to Fedora 11 Problems and Solutions, Applications, Repositories, Hardware, Networking, Tips & Tricks, Servers, Helpful Fedora Websites



Fedora 11 (Leonidas) was released on the 9th of June 2009.

All information related to fedora 11. You can click the contents below.

You don't have to search anywhere in the web for information.

Contents

Oracle Database 11g installation On Fedora 11

1.Download Software

http://www.oracle.com/technology/software/products/database/index.html

2.Unpack Files

unzip filename.zip

3.Pre installation tasks

      1.Following lines should be appended to the "/etc/sysctl.conf" file. 
kernel.shmall = 2097152
kernel.shmmax = 2147483648
kernel.shmmni = 4096
# semaphores: semmsl, semmns, semopm, semmni
kernel.sem = 250 32000 100 128
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default=4194304
net.core.rmem_max=4194304
net.core.wmem_default=262144
net.core.wmem_max=262144


2.Run the command to change the current kernel parameters:
/sbin/sysctl -p

3.Add the following lines to the /etc/security/limits.conf file:

oracle              soft    nproc   2047
oracle hard nproc 16384
oracle soft nofile 1024
oracle hard nofile 65536
4.Add the following line to the /etc/pam.d/login file, if it does not already exist:
session    required     /lib/security/pam_limits.so
session required pam_limits.so
5.Disable firewall

6.Disable secure linux by editing the /etc/selinux/config file
SELINUX=disabled

7.Install the following packages:

su -c 'yum install binutils glibc glibc-common libgcc libstdc++ make elfutils-libelf
elfutils-libelf-devel glibc-devel gcc gcc-c++ libstdc++-devel unixODBC unixODBC-devel
libaio libaio-devel sysstat compat-libstdc++-33'


8.Create new groups and users:

groupadd oinstall
groupadd dba
groupadd oper
groupadd asmadmin

useradd -g oinstall -G dba,oper,asmadmin oracle
passwd oracle
9.Create the directories in which the Oracle software will be installed:

mkdir -p /u01/app/oracle/product/11.1.0/db_1
chown -R oracle:oinstall /u01
chmod -R 775 /u01


10. Edit /etc/hosts

File must contain a fully qualified name for the server:
    
Example: 127.0.0.1 acerfedora localhost

11.Login as root and issue the following command:

xhost + "machine_name"
12.Edit the /etc/redhat-release file replacing the current release information (Fedora release 11 (Leonidas)) with the following:
redhat release 5

12.Reboot your system and login as oracle user

4.Installation


Start the Oracle Universal Installer (OUI) by issuing the following command in the database directory:
./runInstaller

1.Enter password
2. Continue

3. Check user verified for network
4. Note down paths

6.Click password management and unlock accounts you need 7. Installation succesfull



5.Post Installation

1.Edit the /etc/redhat-release file restoring the original release information:
Fedora release 11 (Leonidas)
2.Edit the /etc/oratab file setting the restart flag for each instance to 'Y':
DB11G:/u01/app/oracle/product/11.1.0/db_1:Y

3.Edit /home/oracle/.bash_profile file and ass the following at end of file
# Oracle Settings
TMP=/tmp; export TMP
TMPDIR=$TMP; export TMPDIR

ORACLE_HOSTNAME="machinename"; export ORACLE_HOSTNAME
ORACLE_BASE=/u01/app/oracle; export ORACLE_BASE
ORACLE_HOME=$ORACLE_BASE/product/11.1.0/"db_2"; export ORACLE_HOME
ORACLE_SID=orcl; export ORACLE_SID
ORACLE_TERM=xterm; export ORACLE_TERM
PATH=/usr/sbin:$PATH; export PATH
PATH=$ORACLE_HOME/bin:$PATH; export PATH

LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib; export LD_LIBRARY_PATH
CLASSPATH=$ORACLE_HOME/JRE:$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib; export CLASSPATH

if [ $USER = "oracle" ]; then
if [ $SHELL = "/bin/ksh" ]; then
ulimit -p 16384
ulimit -n 65536
else
ulimit -u 16384 -n 65536
fi
fi
Note: Verify parameters with your own values






Sunday, July 12, 2009

Cheese

Cheese uses your webcam to take photos and videos, applies fancy special effects and lets you share the fun with others.

June 2009: Stable version 2.26.3 was released!

Download... http://projects.gnome.org/cheese/


Fedora 11: I think it's time for you to change!


Fedora is a Linux-based operating system that showcases the latest in free and open source software. Fedora is always free for anyone to use, modify, and distribute.

You can download it here: http://fedoraproject.org/en/get-fedora

Visit the website to know more: http://fedoraproject.org/

RPM Fusion.. Resources are Unlimited....


RPM Fusion provides software that the Fedora Project or Red Hat doesn't want to ship. That software is provided as precompiled RPMs for all current Fedora versions and Red Hat Enterprise Linux 5; you can use the RPM Fusion repositories with tools like yum and PackageKit.

http://rpmfusion.org/

Monday, July 6, 2009

Multimedia on CentOS 5




Step 1: Add the RPMforge repo (needed for majority of multimedia files)

rpm -Uhv http://rpmforge.sw.be/redhat/el5/en/i386/rpmforge/RPMS/rpmforge-release-0.3.6-1.el5.rf.i386.rpm

Step 2: Add the Macromedia repo (optionally needed for flash)

rpm -Uhv http://linuxdownload.adobe.com/adobe-release/adobe-release-i386-1.0-1.noarch.rpm

Step 3: Install multimedia applications (command line to install required packages)

yum install libdvdcss libdvdread libdvdplay libdvdnav lsdvd mplayerplug-in mplayer mplayer-gui compat-libstdc++-33 flash-plugin gstreamer-plugins-bad gstreamer-plugins-ugly gstreamer-ffmpeg libquicktime

Step 4: Installing w32Codecs (required for xvid and other proprietary formats)

wget www1.mplayerhq.hu/MPlayer/releases/codecs/mplayer-codecs-20061022-1.i386.rpm ; rpm -ivh mplayer-codecs-20061022-1.i386.rpm
wget www1.mplayerhq.hu/MPlayer/releases/codecs/mplayer-codecs-extra-20061022-1.i386.rpm; rpm -ivh mplayer-codecs-extra-20061022-1.i386.rpm

You should now have full multimedia and video support for most popular formats.

For other linux users, you can visit this link for mplayer codecs and download rpm

www1.mplayerhq.hu/MPlayer/releases/codecs/mplayer-codecs-20061022-1.x86_64.rpm

www1.mplayerhq.hu/MPlayer/releases/codecs/mplayer-codecs-20061022-1.x86_64.rpm

Saturday, May 9, 2009

Wednesday, March 11, 2009

Language pack


just type: yum groupinstall malayalam-support

You can add any languages, just replace "language" with any language

yum groupinstall "language"-support

Thursday, February 26, 2009

Apache Tomcat Server


You can install by typing: yum install tomcat5

To start/stop the service:service tomcat5 start/stop

To install some sample pages, type:yum install tomcat5-webapps tomcat5-admin-webapps

One more thing you have to so is change the port no 8080 to any(i gave 1986)

by editing:/etc/tomcat5/server.xml

Check whether its working by typing in browser:http://localhost:1986/

Start working with your project....

Tuesday, February 10, 2009

Apache HTTP server in linux(centos 5)



Just start the service by:

service httpd start from terminal

include your files in, /var/www/html

To check whether server is working, type

http://localhost:9999/

Note:i gave port no as 9999

You can configure by editing the /etc/httpd/conf/httpd.conf file using gedit or vi

Screen shot:

Monday, February 9, 2009

Wine:Run Windows applications on Linux




Run windows applications in linux... just install Wine....

For centos:yum install wine

or u can download, http://www.winehq.org/

To install an application:

wine applicationpath/filename.exe

See the screenshots of installing DreamWeaver in linux







Saturday, February 7, 2009

Java on CentOS 5



Installing Java on CentOS 5:

Download the file.....

http://java.sun.com/javase/downloads/index.jsp

If you download the .bin file,,

In terminal,

chmod 777 filename

The file will become rpm file.. then simply type,

./filename

After installing... Path has to be set...

edit the bashrc file in /etc/bashrc

use gedit bashrc for editing..

Add the 2 lines..
export JAVA_HOME=/etc/Softwares/jdk1.6.0_12
export PATH=/etc/Softwares/jdk1.6.0_12/bin:$PATH

Give the path according to your installation...

execute the command:source bashrc

Finally Check: java -version.... It will give
java version "1.6.0_12"
Java(TM) SE Runtime Environment (build 1.6.0_12-b04)
Java HotSpot(TM) Client VM (build 11.2-b01, mixed mode, sharing)

If it is properly installed..

Friday, February 6, 2009

All in one Dictionary:StarDict on CentOS 5




First, yum install stardict


For, Oxford Advanced Learner's Dictionary/WordNet

Download the rpm and install it...

http://stardict.sourceforge.net/Dictionaries_dictd-www.dict.org.php

You can download the rpm and install as many as you want... All in one

Thursday, February 5, 2009

ClamAV:AntiVirus for linux(on CentOS 5)

Any Worries about Virus in CentOS 5... Here is the AntiVirus.....

Type yum install clamav

For GUI interface yum install clamtk

To update database type:freshclam

Wednesday, February 4, 2009

Bluefish Editor on CentOS 5




Programmers and Webdesigners who likes to work in CentOS, Bluefish is a powerful editor with many options to write websites, scripts and programming code..

For more details, http://bluefish.openoffice.nl/

Simply type, yum install bluefish

It will get installed in your machine....

CHM Viewer on CentOS 5


Don't worry seeing *.chm files... Here is the chm reader.....

http://dag.wieers.com/rpm/packages/gnochm/

Before installing, install dependencies by

yum install python-chm

Then, download and install,, rpm -i filename

Pidgin:The universal chat client on CentOS 5



Pidgin is a free chat client... U can download the repo file and install....

Supported chat networks:

  • AIM
  • Bonjour
  • Gadu-Gadu
  • Google Talk
  • Groupwise
  • ICQ
  • IRC
  • MSN
  • MySpaceIM
  • QQ
  • SILC
  • SIMPLE
  • Sametime
  • XMPP
  • Yahoo!
  • Zephyr


Download it here......

http://www.pidgin.im/

Sunday, February 1, 2009

Animation:Blender on CentOS 5


For your
Animation Works...
Blender is a good software...

Here is the link...

http://www.blender.org/download/get-blender/

or

Download the following rpms & install...

From terminal rpm-i filename

fltk-1.1.8-1.el5.i386.rpm
OpenEXR-1.4.0a-4.el5.i386.rpm
blender-2.45-17.el5.i386.rpm

from http://rpm.pbone.net/

Saturday, January 31, 2009

Virtual Vista on CentOS 5






CentOS provides virtualization so that you can install any other OS and you wil be able to switch between them.... like having different windows opened in a screen.... i will post some snaps of my lap..

Here is the vista ultimate installed in CentOS5...

Friday, January 30, 2009

Mounting Windows partitions on CentOS 5



CentOS is an Enterprise Linux distribution based on the freely available sources from Red Hat Enterprise Linux... While installing you have to choose custom layout so that it will dual boot with windows.. In my system Windows XP, Windows Vista and CentOS5 is working together... In order to access data from windows partition and to write data you need to install a software(fuse) and also you need to upgrade your kernel to latest version... For that you can just type(yum update as root)...

Install:
yum install fuse fuse-ntfs-3g dkms dkms-fuse

Then you can mount by:
mount -t ntfs-3g /dev/??? "/mnt/???"

You can check the partition by:
fdisk -l

CentOS


I am a CentOS User..

I recommend it to,

those who likes to have a nice experience working in linux

You can download it from here...

http://isoredirect.centos.org/centos/5/isos/i386/