当前系统为CentOS Linux release 6.4 (Final)，内核版本为2.6.32-358.el6.i686.将内核升级至3.4.56最新版本。
1、查看当前系统内核
uname -r
2 2.6.32-358.el6.i686
2、下载linux-3.4.56内核包
cd ~
wget -c https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.4.56.tar.xz
tar -Jxvf linux-3.4.56.tar.xz
mv linux-3.4.56 /usr/src/linux-3.4.56
cd linux-3.4.56
3、配置内核并安装
make mrproper #清除环境变量，即清除配置文件
make menuconfig #在菜单模式下选择需要编译的内核模块
make clean #确保所有东西均保持最新状态.
make bzImage #生成内核文件
make modules #编译模块
make modules_install #安装模块
make install #安装
4、编辑 /etc/grub.conf 文件，将 default=1 改为 default=0
cat /etc/grub.conf
grub.conf generated by anaconda
#
Note that you do not have to rerun grub after making changes to this file
NOTICE: You have a /boot partition. This means that
all kernel and initrd paths are relative to /boot/, eg.
root (hd0,0)
kernel /vmlinuz-version ro root=/dev/mapper/VolGroup-lv_root
initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=1
timeout=3
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (3.4.56)
root (hd0,0)
kernel /vmlinuz-3.4.56 ro root=UUID=2c06f495-2f8c-4930-8968-9c612d32edc1 rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_NO_MD crashkernel=auto LANG=zh_CN.UTF-8 rd_NO_LVM rd_NO_DM rhgb quiet
initrd /initramfs-3.4.56.img
title CentOS (2.6.32-358.14.1.el6.i686)
root (hd0,0)
kernel /vmlinuz-2.6.32-358.14.1.el6.i686 ro root=UUID=2c06f495-2f8c-4930-8968-9c612d32edc1 rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_NO_MD crashkernel=auto LANG=zh_CN.UTF-8 rd_NO_LVM rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-358.14.1.el6.i686.img
title CentOS (2.6.32-358.el6.i686)
root (hd0,0)
kernel /vmlinuz-2.6.32-358.el6.i686 ro root=UUID=2c06f495-2f8c-4930-8968-9c612d32edc1 rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_NO_MD crashkernel=auto LANG=zh_CN.UTF-8 rd_NO_LVM rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-358.el6.i686.img
5、重启系统,并查看内核
reboot
uname -r
3.4.56