Benefits of a custom kernel?
 

Hi,

I have been browsing around google to try and find some how-to's for recompiling the 2.6 Kernel. One question struck me - *why* do I want to recompile the kernel?
Just to say *I have* (almost like another step up the ladder when learning Linux) or is there actually a good reason to do so?

1. What are the performance increases after a freshly recompiled kernel?

a) for a Server
b) for a Desktop/Workstation

(i.e. any benchmark numbers we can discuss, as we computer nerds seem to be obsessed with numbers.....?)

2. What are the downsides to attempting a recompile?


All opinions appreciated (as long as they are constructive.... :-)

Well the big downside is that it's very easy to get it wrong in some way and end up with a system that won't boot. The reason you might want to do it are up to you. Sometimes you need to recompile the kernel to enable support for some hardware or something. Maybe a new kernel has a new feature? If it ain't broke, don't fix it. (unless you want to)

There are a bunch of reasons to compile a new kernel. I did it the first time for security reasons, because I didn't want to allow modular code in my kernel (being able to inject code into the kernel space is definitely a security risk if your paranoid like I am...).

Other reason's I can think of off the top of my head..... To add functionality you need, to reduce size (get ride of stuff you don't need), to upgrade to a version not currently offered by your particular distribution yet....

That is all I can really think of now.

There really are no downsides, providing you follow the golden rules.

1. Always keep a known good kernel image around.
2. Always keep an option on your bootloader to boot that previously stated known good kernel image.

Last thing you want is to have to dig out a boot disk to get your system up and running.

If your going to bother with compiling a new kernel you should look into the grsecurity patches. grsecurity adds some great options to help you lock down your system.