Category Archives: Configuration

Building RPM Kernel Packages

Extract and customize the kernel

1. Log in as root, extract the kernel sources:

tar jxf linux-.tar.bz2 -C /usr/src

2. Customize the kernel with make menuconfig, make xconfig, etc… Create two copies of the .config file and save them in /usr/src/linux<version>-:

.config: this copy has to provide the configuration for the single processor kernel
.config_smp: this copy has to provide the configuration the dual processor (SMP) kernel

3. Copy the linux<version>-.tar.bz2 you downloaded in /usr/src/redhat/SOURCES/

4. Copy my_kernel.spec in /usr/src/redhat/SPECS/

5. Customize the fields Version, Release, description and kernel24 definition in my_kernel.spec. Please note that:

Version has to be the kernel version (e.g. “2.4.33”)
Release should be customized (e.g. “xeon_1.0”). Release will be used for the “EXTRAVERSION” variable in the main kernel Makefile, so you should get at the end that the output of “uname -r” is exactly Version-Release (in this case “2.4.33-xeon_1.0” and “2.4.33-xeon_1.0smp” for the SMP version).
Set kernel24 1 if you are compiling a 2.4 kernel, 0 if it is a 2.6 kernel.

Rebuild the kernel

To recompile the kernel:

rpm -ba /usr/src/redhat/SPECS/my_kernel.spec


rpmbuild -ba /usr/src/redhat/SPECS/my_kernel.spec

You should get two binary packages (kernel-* and kernel-smp-*) in: /usr/src/redhat/RPMS/i386/


Leave a comment

Filed under Configuration, Linux, Tips

Securing your system from Internet threats using OpenDNS

Changing your Deault DNS provided by the ISP to OpenDNS makes the Web experience more secure and more customized. You can block several sites having viruses, spywares, pornography etc. in a simpler way. Also you can make shotcuts for adreesses that are easy to use with. For example, you only need to type mail to go to if you set the shortcuts properly using OpenDNS. This service is free of cost, and its much faster.

To use OpenDNS you need to register an account at OpenDNS. If you’re using broadband internet such as BSNL, you need to setup the Primary and Secondary DNS to OpenDNS. To do this, follow

  1. Type/Click in your browser to go to your DSL Router / Modem
  2. Enter Username and Password (May be both are admin)
  3. Select DNS and use custom instead of Default DNS. Enter the Primary and secondary DNS as and
  4. Save and reboot the DSL Router.

You can change the settings at OpenDNS Dashbord. Use your security level and shortcuts.

You also need a client side program called ddclient for active communication with OpenDNS (To report your dynamic IP addresses to OpenDNS). It can be downloaded at Windows and Mac versions are available at OpenDNS site. For Ubuntu it is availabe via Synaptic.

sudo apt-get install ddclient

The configuration file for OpenDNS is like (in /etc/ddclient/ddclient.conf)

## OpenDNS



Filed under Configuration, News, OpenDNS

Must have Firefox Extensions

  1. Adblock Plus
  2. Autofill forms
  3. Datafox
  4. Download Statusbar
  5. Fix-ml
  6. Flash Video Resources Downloader
  7. FlashGot
  8. NoScript
  9. ShowIP
  10. ShowMyIP

Leave a comment

Filed under Applications, Configuration, Linux, Tips, Ubuntu

Speed Up your Linux

  • Prelinking

1. Activate Ubuntu universe sources. This can be done in Synaptic, or by editing the /etc/apt/sources.list file.
2. Use apt-get or synaptic to install prelink.
3. Now run:

sudo gedit /etc/default/prelink

4. Near the top of the file find PRELINKING=unknown and change unknown to yes.
5. Now you should start your first prelink, don’t worry it will be faster the next time, MUCH faster. Only the changes since your last prelink will be processed. To start the first prelink, run:

sudo /etc/cron.daily/prelink
  • Disabling Unwanted Services

Look Here to find unwanted services

  • Avahi

You just have to edit /etc/defaults/avahi and set that =1 to =0. If all goes well, it won’t run next boot.

  • Concurrency

If you’re using a dualcore machine, use concurrency mechanism. Edit /etc/init.d/rc and change CONCURRENCY=None to CONCURRENCY=shell

  • Boot Profiling

(1) At the bootup menu (GRUB), select your default kernel. You may need to press ESC to see this menu.

(2) Press e for edit.

(3) Choose the first line (it should start with “kernel”). Press e again.

(4) Move to the end of the line, then add the word profile. Press enter.

(5) Press b to boot.

(6) Let the system boot to the login screen, and wait for all disk activity to stop. Remember, during this one bootup, you’ve told Ubuntu to keep track of all disk activity going on, in order to build that list. Don’t be surprised if it’s significantly slower than your ordinary bootups — that’s why it’s not activated by default, remember?

(7) Reboot your system, and enjoy the results.

Leave a comment

Filed under Configuration, Linux, Tips, Ubuntu

EVDO on Linux

Here is a tip on how to setup the EVDO on Linux. Since the EVDO vendors are not shipping any softwares to support EVDO on Linux, this post might be helpful.

  1. Plug your EVDO to the USB port.
  2. As a root user type
  3. Look for the vendor ID and the Device ID (for BSNL it’ll be 05c6:3197). Note it down.
  4. run (Use ID’s from step 3)
    modprobe usbserial vendor=0x05c6 product=0x3197
  5. run
    gedit /etc/wvdial.conf

    and add the following line

[Dialer Defaults]
Dial Command = ATDT
Flow Control= Hardware (CRTSCTS)
Username =
Password =
Phone = #777
Stupid Mode = 1

Now you can connect to the internet using wvdial.

Leave a comment

Filed under Configuration, Linux

Setting Java (Sun JDK) Class Paths

After you’ve downloaded and installed the latest JDK form the Sun servers, you need to set up the class paths so that you can run java and javac from the terminal (Sun’s JAVA instead GNU GCJ). Here is the steps to set the classpaths

  1. Move the extracted files to /usr/java (if not exist, create a new directory)
  2. open a terminal and type vim .bashrc
  3. Insert the following lines

export PATH=/usr/java/jdk1.6.0_03/bin:$PATH
export JAVA_HOME=”/usr/java/jdk1.6.0_03″
export CLASSPATH=.:/usr/java/jdk1.6.0_03

Save & Exit, then Reboot the system. That’s all

Note: Set your path accordingly. ie if your JDK is 1.5 then the path will be like /usr/java/jdk1.5

1 Comment

Filed under Configuration, Linux, Programming, Tips, Ubuntu

GPRS Connection on Linux

Here is a tip to get GPRS Internet connection in linux using wvdial


  1. Connect your mobile phone in to the usb port using the data cable provided.
  2. Open a terminal and type su ; then enter your root password.
  3. Type lsusb and check whether your mobile pone is detected.
  4. Type wvdialconf /etc/wvdial.conf ; this will configure your mobile phone and detect it as a modem and writes in to /etc/wvdial.conf.
  5. Note down the name of the mobile device shown by the above command; eg: /dev/ttyACM0.
  6. Edit your /etc/wvdial.conf using the command vi /etc/wvdial.conf.
  7. Enter your dialling no: in the line Phone :[number] and Modem=[device]; an example file:
  8. [Dialer Defaults]

    Modem = /dev/ttyACM0
    Baud = 230400
    Init1 = ATZ
    Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
    ISDN = 0
    Modem Type = Analog Modem
    Phone = *99***1#
    Username = A
    Password = B
    Stupid Mode = 1

8. type wvdial to connect to internet; type ctrl+c to exit.

Leave a comment

Filed under Configuration, Linux, Ubuntu