更换 centos6 的内核为 oracle uek 内核
2016/11/16
一、使用 oracle 提供的脚本完整替换
参考：http://www.tuicool.com/articles/IRbU3e
[root@svr205-7 ~]# curl -O https://linux.oracle.com/switch/centos2ol.sh
[root@svr205-7 ~]# sh centos2ol.sh
[root@svr205-7 ~]# yum upgrade
oh yeah，升级完毕，注意upgrade的时候，磁盘空间要足够。
[root@svr205-7 ~]# rpm -qif /etc/redhat-release
Name : oraclelinux-release Relocations: (not relocatable)
Version : 6Server Vendor: Oracle America
Release : 6.0.2 Build Date: Thu 16 Oct 2014 10:08:37 AM CST
Install Date: Thu 28 May 2015 01:50:37 PM CST Build Host: ca-buildj3.us.oracle.com
Group : System Environment/Base Source RPM: oraclelinux-release-6Server-6.0.2.src.rpm
Size : 49559 License: GPL
Signature : RSA/8, Thu 16 Oct 2014 10:41:14 AM CST, Key ID 72f97b74ec551f03
Summary : Oracle Linux 6 release file
Description :
System release and information files
[root@svr205-7 ~]# cat /etc/issue
Oracle Linux Server release 6.6
Kernel \r on an \m
[root@svr205-7 ~]# uname -r
2.6.32-504.23.4.el6.x86_64
[root@svr205-7 ~]# 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/vg_svr2057-lv_root
# initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashp_w_picpath=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Oracle Linux Server Red Hat Compatible Kernel (2.6.32-504.23.4.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-504.23.4.el6.x86_64 ro root=/dev/mapper/vg_svr2057-lv_root rd_NO_LUKS LANG=en_US.UTF-8 rd_NO_MD rd_LVM_LV=vg_svr2057/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_svr2057/lv_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-504.23.4.el6.x86_64.img
title Oracle Linux Server Red Hat Compatible Kernel (2.6.32-431.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/vg_svr2057-lv_root rd_NO_LUKS LANG=en_US.UTF-8 rd_NO_MD rd_LVM_LV=vg_svr2057/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_svr2057/lv_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-431.el6.x86_64.img
title CentOS (2.6.32-431.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/vg_svr2057-lv_root rd_NO_LUKS LANG=en_US.UTF-8 rd_NO_MD rd_LVM_LV=vg_svr2057/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_svr2057/lv_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-431.el6.x86_64.img
问题：如果脚本执行失败（如遇到yum源相关的异常），可能比较麻烦，因为脚本中卸载掉了旧的内核版本的一些依赖包，请引起重视。
二、仅更换一个内核
1）准备安装 oracle uek 内核
[root@test ~]# wget http://public-yum.oracle.com/public-yum-ol6.repo -O /etc/yum.repos.d/public-yum-ol6.repo
[root@test ~]# rpm --import http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6
[root@test ~]# yum install yum-plugin-downloadonly -y
[root@test ~]# yum install --downloadonly --downloaddir=/tmp/ kernel-uek -y
2）安装 uek
[root@test ~]# cd /tmp
[root@test tmp]# yum localinstall kernel-uek*
使用新的内核，编辑 grub 调整启动顺序：
[root@test tmp]# vim /etc/grub.conf
重启系统后查看：
[root@test tmp]# uname -r
2.6.39-400.290.1.el6uek.x86_64
