The Linux Kernel
 

I have a few questions reguarding the kernel. I've heard that linux is only a kernel. Is there any truth to this? Howcome after I upgraded my linux kernel (I have Redhat 8.0) it shows up as 2 linux boot options in Grub? And lastly, how do I remove the older kernel boot option from Grub? Thanks in advance.

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KK
:)

Re: The Linux Kernel
 

This is a highly philosophical question ...
Check out this link :)
I'd recommend following the site up a few levels,
too, because it contains quite essential information
like this, too...


Cheers,
Tink

I think you have two boot options because you have two kernel versions and I'd recommend keeping the other until you really need the space or are really sure your new kernel works under every condition with every process. I don't use grub, but I guess there's a grub.conf or something to edit if you do want to remove it.

I'd agree with the last paragraph of that link, btw - two of my computers run Linux kernels with a bunch of great GNU utilities but if you ask me what my OS is, it's definitely Linux.

I mean, I've replaced half the utilities in my DOS directories but that doesn't mean I'm running a GNU/Hacker X/Hacker Y/DOS system (because I have several GNU ports on it along with a lot of free- and Free-ware) - I'm still running DOS, due to the io.sys and msdos.sys.

Linus & friends "only" wrote the kernel, granted, but without that I'd be running a bunch of GNU ports "only" on a DOS box because there was no kernel. And I can 'less' with the best of 'em on DOS but it's clear to me which system I'm running, to say the least.

It's kind of like the old Reese's peanut-butter cups commercials... "Hey, you got you chocolate in my peanut-butter!" "Well, you got you peanut-butter on my chocolate!" "Mmmm... Tastes great!"

The people at GNU were working on a home-made, free and open Unix work-alike. They wrote all their own code for all the commands and programs that you need to do anything useful with a computer. They figured they would get around to making their own kernel.

In the mean-time, Linus began work on a kernel. The kernel is the lowest level of software. It sits between the user-interface and the hardware. Eventually, somebody started running GNU on a Linux kernel, and our favorite OS was born. This took a bit of pressure off GNU to produce a kernel, but they eventually did in 1999. You can run GNU on a HURD kernel, if you want. I guess it's based on a MACH kernel, from BSDs if I remember correctly. That would make HURD and OS-X cousins.

To remove a kernel, you need to edit your /boot/grub/grub.conf, as digiot wrote, and delete the section pointing to your old kernel. Then, you can delete the kernel and supporting files from /boot/ ... vmlinuz-2.4.18-something, initrd-2.4.18-something.img, and System.map-2.4.18-something. Be sure you are deleting the right ones, otherwise you won't be able to reboot. You can also look in /lib/modules/ for a 2.4.18-something directory. If there are two, matching your old and new kernel versions, then you can delete the whole directory for the old kernel. If there is only one, then it was for both kernels and needs to stay.

You don't NEED to delete your old kernel. It's actually a good thing to have a couple, in case one gets hosed somehow, you should still be able to boot the other. I have at least four on my RH9 laptop... Two stock and a stable custom and an experimental custom. If both kernels use the same /lib/modules/version directory, then it's only costing you a couple megabytes in /boot/ to keep the old kernel.