how to replace kernel on Ubuntu

[Tom H]

> loody wrote:
>> I try to replace the kernel under my Ubuntu.
>> my questions are:
>> 1. what is UUID used for? It seems replace "root=/dev/sda1"
>>     is there any tool or command I have to do to getting this number?
>> 2. from 2.6, we use initramfs instead of initrd, but why we still need
>> to add "initrd" option in menu.lst.
>> 3. is there any restriction of kernel version to replace in Ubuntu; if
>> I replace my ubuntu with older version as 2.6.18, will it be ok?

Rakotomandimby Mihamina wrote:
> 1. # vol_id -u /dev/sda2

NoOp wrote:
> https://help.ubuntu.com/
> 1. Enter 'UUID' in the search bar.
> <https://help.ubuntu.com/community/UsingUUID>
> 2. Enter 'initrd' in the search bar. Click on 'Technical'
> <http://manpages.ubuntu.com/manpages/jaunty/man7/bootparam.7.html>
> Also:
> http://www.gnu.org/software/grub/manual/html_node/index.html


I would add to above:


1. I prefer blkid and file to vol_id because I can get all my
partitions' UUIDs with one command:

blkid /dev/sda*

file -s /dev/sda*

(somehow, vol_id /dev/sda* does not work)


2. See also:

http://www.linux.com/learn/linux-training/92607-the-kernel-newbie-corner-qinitrdq-and-qinitramfsq-whats-up-with-that

http://www.linux.com/learn/linux-training/114923-the-kernel-newbie-corner-qinitrdq-and-qinitramfsq-some-unfinished-business