This example uses Fedora Core 4. Other distros will be similar, but not identical.
- Optimizing for a particular processor
- Adding specific drivers: “disk-only” drivers for some IDE disks, and issues with IDE CD-ROMs
- Removing unnecessary drivers (most are external modules, but some are internally compiled)
- Networking: Gigabit ethernet vs 100 Mbps, iSCSI, Fibre Channel
- Queuing: real-time devices
- Upgrading: moving a current system to a newer kernel
Create an emergency boot disk for your system before you go any further.
Insert a blank floppy disk in your first disk drive (/dev/fd0). First, you need to know the version of your kernel. Issue the command:
uname -r #for a short listing
or
uname -a #for a long listing
Write down the kernel version. Typically it will be something like 2.4.21-20. Now insert a floppy in the drive and command:
mkbootdisk –device /def/fd0 2.4.21-20 #replace 2.4.21-20 with your kernel version
Also note that one critical update may need to be performed on 2.4 kernel systems to upgrade to 2.6 kernels: you might have to update module-init-tools.
Kernels have three numbers. The 2.6.12 kernel, for instance, has a:
- Major number of 2
- Minor number or 6
- Revision number of 12
The kernel itself is frequently named “vmlinuz”.
Determine Your Current Kernel Version
In most distros:
uname –a
gives you a long listing of your kernel information
uname –r
gives you the kernel version only
In Red Hat use :
cat /etc/redhat-release
or
cat /proc/version
Review the Kernel ReadMe
Resource: Digital Hermit’s Kernel How-To