How to upgrade my kernel , and saving the old kernel modules
 

Dears,

I have a huge list of questions regarding the kernel upgrade which i need an answer to please, first my platform is RHEL4 with Nahant update 7 , my kernel is 2.6.9-78.ELhugemem i need to upgrade it and install a fix for a bug with package kernel-hugemem-2.6.9-78.0.1.EL.i686.rpm , my questions is as below.

1 - Will the new kernel make a new initrd file with it or use the old one.
2 - There are already many modified kernel parameters will it be lost or reset after the new kernel upgrade.
3 - Configurations like the network bonding , will it be impacted after the kernel upgrade (I am using network bonding and as you know we propagate some modules to the network in the network bonding configurations)
4 - there is some modules already loaded in the current initrd disk , will this be totally discarded with the new initrd image brought with the new kernel.
5 - What is the difference between 'adding a module to the initial ram disk by rebuilding it' and 'add the module directly in the /etc/modprobe.conf'

Hi,

1. it will generate a new one
2. kernel params in /boot/grub/menu.lst will be copied to the new entry
3. bonding config shouldn't have any issues, it's possible if the detection order of the nic's changes and you don't have HWADDR set in your network config's... but pretty unlikely due to a kernel upgrade.
4. generally not, depending on how the extra modules were added to the initrd image. if you manually unpacked the initrd and modified it you could be in trouble, but if you used mkinitrd you should be fine.
5. you only really add modules to initrd if you need them early on in the boot process (think mass storage), /etc/modprobe.conf is read later on (think network drivers, bonding, etc).

As a side note, /etc/modprobe.conf is deprecated now.. add files under /etc/modprobe.d/

cheers

I am a little confused about point four , what is the difference "if i manually unpacked the image and modified it" or "modified it using the mkinitrd" , at the end when installing the new kernel version it will come with the its new initrd image and will totally discard the old one

mkinitrd will generate an initrd based on arguments and the contents of /etc/modprobe.conf, if you hacked about with the initrd manually then things might not match up. You most likely have nothing to worry about - all that's really needed is mass storage driver and file system drivers and these will be detected. When you say "there is some modules already loaded in the current initrd disk", that doesn't tell us what sort of modules they are, if they're storage related you should be ok.

cheers