Praji’s Weblog

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RED HAT

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1. Get the kernel source
	http://www.kernel.org/pub/linux/kernel/v2.6/

2. Check the server settings
	lspci
	lsmod
	cat /proc/cpuinfo

3. Download the kernel
	cd /usr/src/kernels
	wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.21.tar.gz
	tar -zxf linux-2.6.21.tar.gz
	cd linux-2.6.21

4. Configure the kernel
	cp /boot/config-`uname -r` .config
	make menuconfig

5. Prepare kernel image
	make bzImage

6. Install Kernel modules
	make modules
	make modules_install

7. Install the kernel
	make install

	     or
	Do the following
	a) cp .config /boot/config-2.6.21
	b) cp arch/i386/boot/bzImage /boot/vmlinuz-2.6.21
	c) cp System.map /boot/System.map-2.6.21
	d) mkinitrd /boot/initrd-2.6.21.img 2.6.21

	Now alter grub
	vi /etc/grub.conf
        Add line
              title CentOS-4 i386 (2.6.21)
        		root (hd0,0)
        		kernel /vmlinuz-2.6.21 ro root=LABEL=/ panic=3
        		initrd /initrd-2.6.21.img

8. Set the grub to load the new kernel after reboot
	Type grub in the console
	Type	savedefault --default=1 --once

9. Reboot the server
	reboot    		

10. Check the kernel version
	uname -a

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DEBIAN

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1. Install the required packages:
	apt-get install kernel-package libncurses5-dev fakeroot wget bzip2

2. Download the latest kernel
	cd /usr/src
	wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.19.2.tar.bz2
	tar xjf linux-2.6.19.2.tar.bz2
	cd linux-2.6.19.2

3. Select the required kernel features and compile the kernel source
	make menuconfig
	make-kpkg clean
	fakeroot make-kpkg --revision=custom.1.0 kernel_image 

4. If the compilation stops with an error, run
	make clean

	and then re-run the previous commands starting with
	make menuconfig

5. Go ahead with
	cd ../
	dpkg -i kernel-image-2.6.19.2_custom.1.0_i386.deb

	This will install your new kernel and also update grub configuration file.

6. Create a ramdisk of your new kernel, otherwise your system will most likely not boot:
	cd /boot/
	mkinitrd -o /boot/initrd.img-2.6.19.2 2.6.19.2

7. Now edit /boot/grub/menu.lst and put the following entry after the kernel directive of the new kernel:
	initrd  /boot/initrd.img-2.6.19.2

	But if the /boot is on a separate partition, the entry should be as follows:
	initrd  /initrd.img-2.6.19.2

8. Reboot your machine with new kernel:
	shutdown -r now

9. If everything is ok your machine should come up with the new kernel. You can run
	uname -a