Linux Kernel

ollielaroo

Can anyone help me?
I know a little about linux. I need to know what the kernel is about.

How many MB it typically takes up?
Is it hardware specific?
What are its functions?
I hav installled Redhat9 sucessfully on an old Dell Dimension XPS D233 (P2) with 256 MB Ram. For waht reasons would I need to replace or patch the kernel?

Thank you.

Zombrex

ollielaroo wrote:

Can anyone help me?
I know a little about linux. I need to know what the kernel is about.

How many MB it typically takes up?
Is it hardware specific?
What are its functions?
I hav installled Redhat9 sucessfully on an old Dell Dimension XPS D233 (P2) with 256 MB Ram. For waht reasons would I need to replace or patch the kernel?

Thank you.

The "kernel" is the main part of the operating system, that controls all other programs running on the PC, and controls underlining access to the PC hardware (all other programs talk through the kernel to get to the hardware)

When you compile the source code for the linux kernel (www.kernel.org) you can decide what options and hardware support you want included in the kernel. Older Linux distributions came with a large kernel with a lot of hardware support included, but if you are compiling your own version of the kernel you can ignore hardware which you don't have, thus reducing the kernel size.

Depending on how you compile the Linux kernel the size can range from very small (versions on the kernel can fit on a 1.4MB floppy disk), to massive in size 100MB+, depending on what options you include.

Recent versions of the linux kernel included support for dynamic modules. These modules can support hardware that used to have to be included in the kernel itself, and can be loaded at boot time.

So with a modern Linux distribute you will probably have one smallish main kernel and load of modules installed.

Only the ones specific for your machine's hardware and options will be loaded at boot, which reduces the amount of RAM the kernel needs to take up. If you need the harddrive space back you can uninstall any modules you never use (modules for hardware you don't have), where as before it was all or nothing in the kernel.

A reason to upgrade to a new version of the kernel is to allow for support of new hardward and features, and very occationally to fix security bugs in your version of your kernel. It is a myth that you need to (or even should) upgrade your kernel all the time with every new release.

If your kernel is working fine for your machine's hardware, then it is probably best to leave it as it is, unless you are effected by any bugs in that version of the kernel.

ollielaroo

Thanks Wicknight.

I am qualified in Tech Support, mainly windows. I'll be starting a new job soon which will involve mostly command line tasks on linux boxes. I am not a programmer but have been exposed to some basic admin bash scripts. Do u know any good sites where I get to know how simple perl scripts work?

Zombrex

ollielaroo wrote:

Thanks Wicknight.

I am qualified in Tech Support, mainly windows. I'll be starting a new job soon which will involve mostly command line tasks on linux boxes. I am not a programmer but have been exposed to some basic admin bash scripts. Do u know any good sites where I get to know how simple perl scripts work?

Perl can get quite hard to remember, I would recommend that if you are going to be doing a lot of Perl (is this a webhosting company you work for?) you should buy a book on Perl. It will be worth it in the long run, since you won't have to be remember all the different webpages you have looked at.

Not sure which book to recommend since I haven't touched Perl since college. The O'Reilly books are generally good, so to are the No Strach Press books. Perhaps post a request for a good book in Programming forum.

If you want to learn more about Linux and the bash shell I would recommend the online books (called "Guides") on the linux doc project (www.tldp.org)

ollielaroo

Thanks wicknight,

Not web server stuff.

May I show u the job spec..

philologos

The shell is easy enough, but Perl will take a while to master. Get yourself some books from O'Reilly maybe (www.oreilly.com)

Zombrex

ollielaroo wrote:

Thanks wicknight,

Not web server stuff.

May I show u the job spec..

As Jakkas says, get a book on Bash and a book on Perl, install a modern Linux distrubution (Fedora is probably a good bet since the job is RedHat) and start messing around with scripts and commands