Error building kernel rpm files

I am building a CentOS 6.3 kernel with Web100.Org mods applied.The build seems to complete OK and I can boot the new kernel.I used dracut to generate the initramfs.img file.

Building your own kernel is strongly discouraged.See I Need to Build a Custom Kernel. [by YBellefeuille]

I haven't tried building a CentOS 5.x AMI but I recently built a CentOS 6.0 AMI using PVGRUB. If the kernel in 5.6 supports it (and I believe it might) then you don't need a xen kernel f... [by matjones]

I haven't tried building a CentOS 5.x AMI but I recently built a CentOS 6.0 AMI using PVGRUB. If the kernel in 5.6 supports it (and I believe it might) then you don't need a xen kernel f... [by matjones]

I stalled a Centos 4.8 with Kernel 2.6.9-89. And now I want to re-build the kernel for Disable USB device except USB mouse.It said:"Linux wspc1062 2.6.9-89.ELsmp #1 SMP Mon Jun 22 12:31:... [by sanderschen]

Does anyone know where I can get the linux spi headers for CentOS 5? I need spidev.h to build UHD, but it doesn't exist in kernel-headers as it does in CentOS 6. /UHD/uhd-source_... [by jjhein]

ok.. solved... I was building against the kernel-devel... when I need to build agains kernel-xen-devel!Bill [by idbill]

i'm user centos 6.3 kernel 2.6.32and i want to modified and patch kernel such as l7layer, pp2p to new kernel version 2.6.35download kernel source (tar.gz) from kernel.o... [by slackman]

Hi can some one help me in understanding this.

On Centos 6.2 its showing kernel as 2.6.32-220.el6.x86_64

whereas on Ubuntu 12.04 its showing as 3.2.0-23-generic.

3.0 kernel is one of the latest kernel and Ubuntu is using that, whereas Centos is using an old kernel. Why is it so?

Can an old kernel offer every new feature that a new kernel can? Why aren't they upgrading to 3.0?